Back to square one on this quad. Does anyone know why this would have blown up so quickly? Please SUBSCRIBE and LIKE the video if you enjoyed! It really helps me out a lot! Check out my Instagram: 2_vintage_ Thank you for all the support! I'm not giving up on this quad yet!
LT250r-500r motors are supposed to have thrust washers one each side between the piston and needle bearing, I would get billet made ones as the factory steel would cause tremendous damage when they came part. Also check the main crank bearings for play, as I have seen that cause the same issue your having.
Leak down test is a must. Honestly! You had the cylinder off along with all the intake components. You could have air being sucked in like crazy around the intake boots. They are notorious for leaking on Suzukis. I have been playing with lt250s for years now and have built plenty motors. I would never consider putting any engine into a frame and starting it after rebuild without first leak testing. I think it was running extremely lean, there was basically no smoke. Almost nonexistent.
@@Chris-ru5eq I've told him over and over and over again about doing leak down tests using proper tools he takes all his bolts out and put some in with an impact driver he takes stuff doesn't drain the gas doesn't drain the oil just trust what someone else has done or trust what someone else has told them if he had took this cylinder and had to measure the clearances for himself before he ever installed it he would not have had this problem not only that but the shop that did the job didn't use torque plates that's why it has scuff marks in the four corners of the piston that's a very common thing when the boar isn't perfectly round if the bike had a ran any longer it would have had a cold seizure he was running factory Jets meanwhile it's bored out it's not big enough where you would consider it a big bore but I have a 421 Cub Banshee and I know all about leak down tests and what can happen if you don't do a leak down test
Yeah it didn’t even sound right.. could just be the camera and shit but I have built a few zillas in my day and ridden plenty of 500s it did not sound like any zilla I ever heard
@@Chris-ru5eq I know how you feel, I too have commented on his lack of cleanliness (works on filthy engines and carbs) and his "RUclips knowledge" I watch for the laughs and to see how long it takes to blow 'em up. !!
Having the same issue with a Kx85. Couple things to double check Joe 1. Rod bearing 2. Check for grooves in your rod where the wrist pin bearing sits 3. Ring gap 4. You may need a higher flow Petcock 5. Stator side crank seal (could be getting too much air) 6. Timing?
If we're just guessing, id say the small end of the rod is bent, causing the pin to be cocked, causing the piston to sit just a little off in the cylinder. It would explain the tight pin, stuck rings, and the scoring. Just a guess though. Good luck!
Came here to say something similar but you explained it in a much smarter way😂 but yeah and the fact it happened twice in what looks to be pretty much the same spot.
At First start I didn't see any smoke, mixed that rich it should have been immediate and thick from the tailpipe. Makes me wonder if the crank seals are bad or needing to be doubled up on one of the sealing gaskets. The scuffs are happening on the exhaust port side so carb tuning wouldn't be the issue. Sorry Joe that's really crappy.
Bro if the crank seals were bad they would be pouring oil into the crank case and smoking like a son of a bitch and or pouring oil out the stator side causing a leak condition from the vacuum leak learn what you’re talking about before you comment some shit
@@thegoodjelly4950 depends on what side of the crank it's leaking on IF it's leaking, wet side would make it run rich or possibly leak, coolant side would make it burn coolant and smoke like a chimney, they're all possibilities. Instead of acting a fool, try actually helping without a bad attitude. Don't like it ? There's the door.
I appreciate you put a video up that shows us the good and the bad of engine building. Your learning. keep going. Next time. Make sure your piston is facing the right direction. Check your ring gaps Check piston to wall clearance Do a leak down. Wash your cylinder and then wash it again Make sure you have atleast a film of oil on your cylinder wall and your piston when you assemble make sure your crank is lubed. And cycle the engine a few times You can use the 2 stroke oil to lube the parts up before assembly I definitely think it was an issue with your clearances
Not that this has anything to do with the video or what you said but guys tend to put way too much oil on the piston/rings/ and cylinder and then idle it for 20 hours. They end up glazing the cylinder and the thing doesn’t seat the rings. I’ve seen it happen before and had a dude who had blow by at 10 hours. Cylinder was in spec, rings were in spec. Rebuilt it, rode decently after letting it warm up and then ripped it, no blow by at 40 hours, you need a couple heat cycles if it’s a forged piston though due to the structure of the metal and built up stress that needs to be released as it warms up and expands, and cools down and shrinks.
@@aaronbright5028 yes there is, over oiling the rings, cylinder, piston etc on a fresh top end can cause issues just as much as too little oil. I’m a small engine service technician, it’s stuff they teach you about lol. I’m not just a RUclips mechanic I do this stuff for a living. A small amount of oil is fine, I wouldn’t start a 2 stroke up completely dry on a fresh rebuild. But just don’t go nuts with it. As well as the heat cycle break in is not necessary at all with a cast piston, I don’t do heat cycles and use cast pistons on my 2 strokes and they make tons of power and last a long time. Never blown a bike up before and I ride pretty hard.
@@tpghl5225 Ive been the head mechanic at 2 different motorcycle dealerships. I became head of shop at 14 when I started and since then I've built every engine from a small block chevy to a cbr954 all the way down to chainsaws and generators. Born and raised in 2 strokes. Out of probably 1200 or more engines I have only had one issue with over lubing and that's smoke on startup. Never fouled a plug never "glazed" my crosshatch. My top ends drip oil from them when I install them. If over oiling was possible I would have found out already man. 15 years experience half at a dealership and I've heard over oiling myths for all of it. Just listen to the dumbasses that think less premix is more power on a 2 stroke and it's completely opposite. But nobody ever tried it they just follow the myths.
@@aaronbright5028 I’m not questioning your seniority at all, I think the main thing comes from idling a fresh motor without much of any change in rpm when these guys do heat cycles especially if the cylinder doesn’t have a fresh hone. Majority of these guys on here in the comments have worn cylinders, don’t own a torque wrench, and never check their ring gap so it’s really the least of their worries either way but my main point in other comments I’ve said on other videos is just letting the bike idle all day long on the first couple startups. This definitely doesn’t seat the rings as would putting some load on it/just riding it. But like I said forged pistons are a different story on the heat cycles as they do need a few, although you still shouldn’t just idle it
In a prior video it was shown that the piston was extending above the cylinder by approximately 2mm at the top of the compression and exhaust strokes so my theory is that the outer circumference of the piston dome is contacting the underside of the head and compressing the ring lands such that the rings are getting stuck and scoring the cylinder. The thermal expansion of the various metals involved once the engine is warmed up while running may exacerbate this condition that may not be evident during the assembly phase of the process while all parts are at room temperature. It is hard to tell in the video, but it looks like there is a witness mark of potential contact on the outer circumference of the piston dome which helps to lead to this theory. Best of luck in diagnosis and repair.
Excellent Kristi, I have a opening in my Race Shop, if you're looking for work in one of the most progressive Motorcycle Engine Building shops in the East coast. I build Turbocharged, Supercharged, and Naturally Aspirated Motorcycle racing engines. I would recommend that you have a TRUE interest in Harley Davidson and Suzuki to be considered. Thank you and I wish you all the very best in your future endeavors.
Get a better compression tester. That one is clearly busted. There’s no way you have 100psi and are nearly standing on top of the kickstarter. Go get a Bosch one from Oreillys
Hey there kid . I watch your channel quite often and love your enthusiasm . I'm not going to say my age but I'm an old timer compared to you. I've have worked on just about you name it since I was very young , and have forty years of experience repairing and rebuilding engines . it looked like the piston to wall clearance may have been a bit too tight , and also like you said that the ring gap may be too tight also , the basic rule on ring end gap for just about any engine is .004 per one inch of cylinder bore . so for example with a four inch piston you would want a .016 end gap . especially on a engine that you are going to beat the snot out of because the parts are going to get hot and expand a lot . and also make sure you check the ring side clearance in the ring grooves they look like they might be too tight also, and that will definitely make them seize up and cause scoring , they need proper clearance also to stay lubricated . usually .003 -to .005 . remember that is a big piston so it is definitely going to run hot. . and last but not least make sure and shamfer the edges of the rings when you gap them with a fine file or a whet stone . cause one little burr can make one big groove in your cylinder. and make sure you oil it up well when you assemble everything. I hope a bit of this information helps you out and you complete your mission of your project, Stay safe , have fun , and good luck to you man.
Lean on startup and not nearly enough oil applied to parts when assembled, so it was also a dry start. Should up the pilot and main jet sizes by 5 numbers, initially on a new engine. Will run bad and smoke like crazy, possibly foul plug. But that's the lube that a new 2 stroke needs on initial startup. You didn't check the intake boot for cracks or bad gasket. Possibly bad crank seals. Never checked piston to wall clearance. Never checked ring end gaps. Didn't wash cylinder and piston properly before assembly.
Piston was out of spec. It happened to me on my 250r. You do get them from time to time. If the wrist pin or the pin hole is out of spec, the piston wont move in the cylinder like it should and then this happens. Tough break but could have been worse. Still fixable relatively cheap. Check the cylinder bore for out of roundness as well.
If nothing else you show many folks what real men do when something goes amiss after a good repair, I for one would have had a temper tantrum but you sir show you can be very disappointed at something and still be calm and push forward. Respect to you and look forward to your repair...
at this point I’d pull the hole motor apart I bet there’s something up with the crank and you should have checked your piston to wall clearance also make sure your rings are in the right orientation
You need to do the squish test ONLY in line with the piston pin (sides) so you don't have piston rock giving you a false (& smaller) reading. That's why you had all sorts of different measurements. What were the piston to cylinder clearances? Looks like it was possibly too tight. Did the place who bored it chamfer around all the ports? This didn't cause the problem but if it is NOT done, the rings will get eaten fast.
So I noticed when you originally put the cylinder on,that you twisted the cylinder to get it to line up with the base studs.you should never do that because a ring could easily pop out of the Grove if the end gap is in a transfer or exhaust port.buddy of mine had a Honda 250r quad,had to turn or twist the cylinder to line it up,a ring popped out and it rui ed the cylinder and piston. So,if that score in the cylinder lines up with the end gap of a ring,you know what happened.you should always lower the cylinder straight down onto the piston on a 2 stroke,never turn the cylinder after the piston rings are in the cylinder.
Yeah i was looking for this comment and here it is. That's what caused the damage. I know the frame maybe don't have the room for the cylinder to fit in the right way in that case you should remove entire engine to put the cylinder on and then put the engine on the frame.
@@Chris-ru5eq so it was the last video he posted of it,when he put the top end together.and yes,he does find some good machines,I just wish he would listen to some good advice from time to time.usually,I just get smart ass comments from the kids that watch him.worked professionally on bikes quads and snowmobiles for 40 damn years,I know a little bit of what I'm talking about on that stuff.actually had someone tell me the other day that you can put a new chain on old sprockets!!! Lol,that just dont work out!!
@@Chris-ru5eq seen that!! Hell,He'll, time I just said that a set of impact sockets is cheaper than a hospital visit,and you should have seen the shit storm that it brought on me.little kids telling me I have daddy's money and shit,and I was just trying to look out for him.i try really hard to not comment anymore.
Look at the pipe on the inside where it hooked to the cylinder maybe there carbon build up and it pulled some trash in when you started it ? Did you flush out the bottom end before you did the top end ?
Perhaps the piston contacted the head a couple times causing the ring grooves to clamp onto the rings. Something is not the correct dimension. Piston, rod, bearings or head gasket. I don’t think it ran long enough to cause heat damage due to a possible lean condition. But those intake boot do tend to leak extra air into the engine. I’d check the boot if you do find and repair the problem.
@@alanparis7256 I think a piston is to soft to be using solder anyway. I know a lot of people do it that way but I’d be afraid to. It takes a bunch of pressure to mash solder especially with a soft aluminum piston
Was the compression good before it? The piston pin should move freely, but with some older 2 stroke bike they are very tight! The piston + rings should not be damaged that quickly! Did you check the piston ring gap? Another thing that kills pistons that fast is false air. Most of the time its the reedvalve gasket or base basket that causes the problem.
Has the exhaust port been messed with? Has the cylinder been shave?, head shaved?. Measure everything or if in doubt get a completely new top end for it. And jet it super fat and work your way towards the correct mixture
Crank bearing is toast or rod is bent. Crank probably has a lot more play while running then you can realize jus lightly playing with it with your hand
Its either a crank seal or it just wasnt the right piston and ring combo for the build. Regardless of what the measurements seen sometimes it's you have to go with what the engine needs and for running 28:1 I didnt see enough smoke Joe.. it's still running lean somewhere sucking job alot of air
I’d recommend sending the cylinder and piston to a place like ken O’ Conner racing. Those guys are great and can get you the right piston and clearance the rings correctly. Maybe just send the whole engine in so they can make sure the correct rod was also installed
@Kevin Stearns kinda impossible for some. There’s no one in my area that will do the machining or check specs. So I’m forced to send it off. KOR hasn’t done me wrong
I know this sounds weird to some but I'd use regular ol marine 2 stroke oil. I've been using it since I had started riding 2 stroke. I also work on the road department in PA. We have the demo saws for cutting concrete and other things but the county started supplying us with synthetic blend high performance 2 stroke oil because it was cheaper than the pensoil marine 2 stroke oil we used to use. The saws started seizing up after running for 2 minutes and a few of them blew up. I think the synthetic 2 stroke oil does not lube good enough. Also anytime I blew up a 2 stroke bike the cylinder never had scoring and the rings were never stuck. I also don't see any signs of high heat. Also did you lube the cylinder with 2 stroke oil before you put it back together. Under lubrication will cause the rings to stick. What ever may be wrong I hope you figure it out. Also you could have bent the edge of the piston when you were doing you squish test. Next time you do it try not to get it so close to the edge and make sure it is done in line with the wrist pin.
Since there are two scratches and 2 ring end gaps and the rings are stuck in the ring lands...Most likely the rings were filed to open the gap for spec and the ends weren't beveled. When you file rings you have to file the edges so there isn't a high spot at the end gap.
Anyone that blips gas before kicking it over on a 2 stroke or always runs bikes with the fuel on "reserve" not "on" like Joe does really needs to find a new hobby. Might wanna try assembly lube when rebuilding and cycle the piston a few times before trying to start it on a fresh top end.
Piston should NEVER be above the cylinder deck. I bet it was tapping the head outside of the squish area. The piston does cock with inertia while running. To me it sounded terrible while idling. Almost like piston to head.
@@devinlawson4093 then you'd see a lot of damage on the head, i had the same when my crankshaft failed and the whole head looks all dented and messed up.
Good you always giving it a go bro and ta2king the time to upload for everyone. Thankyou bro. I'd check piston clearance first and go from there. And a lil richer on oil mix during break in
Piston clearance with cylinder wall too tight, did you check ring end gap tolerance before installing them onto piston, ring tolerance can be too tight. Metal expands with heat and needs correct tolerances to run smoothly at running temperatures. Take it to a machine shop and have them assess cylinder bore and what size piston you need. When you fix cylinder and have piston, have the machine shop test the ring end gap and resize, file the ends properly if need be. Hopefully you didn't fubar your connecting rod and crank.
did you assemble with plenty of oil? rings installed correctly? ring end gap checked? is that a wiseco piston if you had done everything correctly,ball wiseco support.
Perhaps when you did the quench test, maybe you damaged the piston, look like there were quite a bit of force being pushed up on the piston smashing the solder. Just a thought
I was thinking the same thing and I’ve seen several people on RUclips check the squish with solder . It looks like to me that it would put a extreme amount of pressure on new parts. Plumbers putty or play-Doh left in the fridge for a little bit works best
I would check the crank/crank bearings after watching the variables in your soldering wires it’s high compression so it’s definitely hard on the rods and crank/crank bearings, you said you put the head gasket on backwards and hit it with the piston, I would’ve probably just replaced it and cleaned the piston of any debris by removing cylinder, Try and drown the piston with 2 stroke oil and let it sit and turn it over slowly to lube everything up before your first start, I have seen guys use putty to find squish clearances to but you would have to take the head off and on to get it out. If you get another new head gasket keep the one that blew up if it’s the same thickness and use the old if “it’s not to screwed up” to find the squish clearances with putty or the plastic squish gauges so your not taking the head off and on with a new gasket messing it up, I’m not a professional so take what I say worth a grain a sand hope you figure it out bud
I’ve owned an 88 quadzilla that rebuild from the ground up elkas/good quality parts etc..it looked beautiful when it was done but it wasn’t what I expected it to be then I bought my first banshee I’ve owned rode it once then sold the quadzilla … the quadzilla has some issues that can’t be corrected… even with elka shocks it handled pretty ruff
Buy a new piston. The cylinder looks like it'll hone out. Then after you get it together buy a cheap leakdown tester off of eBay from South texas banshee. Looks like it was lean causing the piston to melt. Leakdown tester is well worth it.
Re route it and wrap it with reflective heat tape where it comes close to the carb to. Is there anything in between the exhaust and fuel tank to block heat? I do not think that either one of these were an issue this time it’s got to be something with clearances
@@brandywine1548 no I’m not saying that’s what caused the problem I’m saying get rid of the fuel line away from as much heat is possible just to be on the safe side I say you split cases put a hot rod crank make it a 700 mL port polished ahead put a CP Perillo piston fuck Wiseco get a good set of tires Reeves and redo that motor Charnette plastic back up new seat cover new hand guards it take that down throttle off and put a dirtbike throttle on it and you will have a bike on your hands that everybody is dying to get it
Hey Joe thanks for the video, I noticed that when you started the bike smoke was not existent. At 28 to 1 there should’ve been quite a bit of smoke especially initially there was zero I’m sure you will go back and watch the video to see this
Use something softer than lead to measure your squish. You would never use a piston to hammer a bit of lead flat on the bench, don't do it in the engine.
Iam doing a full rebuild on a 85 250r motor which was bored to the next available size (66.75). I have just received the new piston first stop for that Is back to the machine shop with the cylinder to confirm clearance is in spec. Iam also doing a new crank and obviously every oil seal and gasket. Before this is fired i will be doing a full leak down test. This way in my opinion will avoid any problems in the near future.
Hey Joe, sorry your going through this , my 2 cents for what its worth , I would run 2 base gaskets ( be prepared for port timing to change ) to relieve that tolerance on the head clearance situation, a bit of work but change crank seals, I also run 40:1 with non oxygenated fuel I all my race bikes aka Can-Am 500 ktm 500 yz490, yz 400 , Husqvarna 500CR , and never a failure under race conditions, most don't know but the thicker you mix your fuel ratio at ( without jetting change ) the leaner your engine will run , double and triple check ring end gap , ps I use Yamabond on all gasket surface since 1985 , best product out there, great video joe 👍 now is the time to dig deep for diagnostic skills , keep up the good fight
There was no issue with head clearance and just like I told the last bean pole crank seals would make the oil leak into the base like hell and it would smoke it’s ass off y’all need to learn how to build a motor
There are two detrimental ring clearances. Rings end gaps people commonly know of. But most don't confirm the ring land clearance. If there isn't enough ring land clearance, as the piston heats up and expands it squeezes the rings and they get stuck. Always ends in disaster. That's what it looked like. I learned the hard way. Also, forged pistons expand more than cast pistons. Forged requires more clearances.
Are you sure your wrist pin won't go back in the piston? Sometimes they got to go in just right cuz they're such a small amount of clearance. Is there an up and a down to the rings ? What you call a scratch to your cylinder wall I've seen the ring end GAP leave a mark like that in cylinder walls before. Is that actually something you can catch your fingernail in? Did you check compression before you ran it so you had a reference?
That motor is sucking air somewhere in the crankcase, it will continue to cook pistons until you find the leak. Tear it completely down and find the problem. I've seen 2 stroke engines burn a hole in the piston from sucking air, seems to happen on older snowmobile motors often.
well.. i don't suspect an air leak as the idle was dropping right back down after releasing. i havent watched the series so not sure how you gapped your rings. not sure how you mixed your fuel with what ratio and oil. how was the crank? in good shape? was the piston installed in correct orientation? what was the piston to cylinder wall clearance? was the cylinder and head nice and level/flat?. other than that. im not to sure. i know how aggravating it is i've had a rm250 like this and a yz80
Metal left in the transfer ports from boring the cylinder that didn't get cleaned out. First time you started it, it sucked all the left over bits of metal that didn't get cleaned out into the cylinder. That's why you have all the scratches on the piston and cylinder and the rings were seized. Top of the piston had oil on it so I doubt it was lack of oil, and you weren't over revving it at all. Not to mention that didn't sound like a seizure when it shut off. Oh and btw, when you're kicking it over, find the hard spot in the stroke and nudge it just past that, then bring the kicker back up and it'll kick over much easier.
are you using an OVERSIDED piston? maybe the box is mislabeled? Its possible once thing heated up they expanded and if you are doing a stock bore with a bigger piston... that's an issue. Check to see if you piston / cylinder clearance is too small.
Thing you need to make sure you never do when installing your cylinder, is make sure it goes on in aliment you never want to spin it left or right as you did. I have a feeling that is why you had this issue.
@@kurtyoung6769 Sometimes it’s a small as shit as a tear of the motor back apart split cases put a hot rod kit in it port and polish the head bore out the jug up to a 700 mL get you a nice CP Perello piston fuck Wiseco make that thing a 700 mL quad banshee Then put a throttle grip like a dirtbike ass and get rid of that dumb shit in new plastic and you’re going to have one hell of a rare motor swell not motorcycle 4Willer on your fucking hands that everybody will want
could be a crap rebore, not perfectly round?. have to be honest i have had hassle both times i have used a wiseco piston ( with running issues) and tend to look for OEM stuff now. not sure both problems you have had with this engine are linked . seems weird the top of piston is oily but piston side is bone dry and has got hot enough to jam the rings up . are both rings identical??? i cant remember with wiseco?
Man, that sucks. Possibly cylinder too tight for the overbore? Did you check that clearance? Ring gap too small? I have my bore guy check those then I check as well.
A few questions, haven't seen all your videos just this one for this banshee. Do you have the tools to measure piston to cylinder clearance? Did you check ring and Gap by putting the rings into the cylinder and checking the Gap with a feeler gauge? I did just buy a set of wiseco banshee Pistons last summer and the ring s in one of the Pistons would stick in the groove so I sent them back and got replacements. I found this before even running it. Just saying could be defective piston.
You smashed the rings in the piston from the piston hitting the head it sounds funny like something is nocking probably the piston bro flipping that gasket Will not keep the piston from hitting the head someone shaved the top of the cylinder to raise the ports changing port time it's a really cool mod but you got to put 2 or 3 base gaskets it depends on how thick they are and how much it needs lifted the edge of the piston should be flat with the cylinder and never stick out looked like you already smashed the piston
i saw that it kinda looked like the piston was to high up the cylinder with head off looked like above the top of cylinder im with u on this one this is the cause an when the pison has nowhere to go it bent the pin clamped the rings an compression was lost somehow possibly bending rod but if the pin was bent maybe lucky either way rebuild crank an rod measure everything 50 times lol seals crank bearings must be a measurement for cylinder height get measurement of cylinder yea yyou can do it you must just think like a mathematition
I agree with everyone saying to do a leak test. It was more than likely sucking air in somewhere making it run very lean. There was a very small amount of smoke coming out the exhaust when it was running.
looks like the piston was way to tight in there, did the company where you get your cylinder machined messured the piston clearance and checked it with the original measures? the reason is, if your piston is to tight and it warms up it looks exactly like this and it melts the piston rings on your piston. is it an aluminium cylinder or a metall one? if it is a metall one its even more important to check the clearences for the piston and the rings.
This doesn’t add much value but things that stood out to me was the extreme lack of smoke on start up. It almost looked like a 4 stroke. I wonder if the cooling system is blocked somehow.. it’s odd that it started leaking (possibly from pressure)?
I just picked up a 1981 rm465 that was essentially abandoned. Could’ve been sitting for like 10years. Anyways got it for free. Is it worth refurbishing it? If so what’s the first step? It has compression
IMO I think the ring end gap was too tight. In the last video when you assembled the top end I don't recall seeing you check it. Usually, the ring end gap spec is provided on a little piece of paper in the box with the new piston/rings. Checking it is crucial because if it is too tight the rings will bind as they heat up and expand.
@@2vintage it doesn't matter if the shop has done it 15 times when you get it back you double check to make sure because that is 100% the shops failure to do the procedure correctly the other issue that could have happened when they board the cylinder out they may not have had the torque plates if you don't torque the cylinder in between the specs that it's supposed to be clamped down by you can actually have a bore job that isn't round
@@2vintage the fact that the shop had to call wiseco to ask for a clearance that on the instructions in the box of the piston shows their non-knowledge of motors because if boring out cylinders you should know what the clearances need to be I know right off the top of my head what the clearances need to be for every inch of bore
I've been watching your vids for a while...you've come a long way but the best way to test if a 2 stroke is sealed internally is a leak down test. Even if your carb is jetted correctly if your sucking air in from somewhere it will create a lean condition. I own an 87 lt500r and have rebuilt the top end a few times now and the bottom end once. I'm not sure what happened here but its good to see a nice healthy plume of smoke from 2 stroke exhaust.
Plume smoke ... Uhhhhhh... I didn't see much .. but ok... If I would fire up my moped on 28:1 I would end mosquitoes on earth ... Yep😐... It's seems to be fubar but I'm not wrench guy... But im the master of blowing shit up.. and yr screwed ..
Maybe its got the wrong crank for that piston and jug. Or crank is worn. Its nothing to do with the jetting or running lean cause you gotta run an engine lean for a while to cause any damage like that.
All the ports inside of cylinder are they completely smooth maybe they haven't been chamford after bore. they can catch onto rings n cause your piston sides to look like that
did you do the rebuilds your self? you generally want to add a generous amount of thick oil around the cylinder and piston rings before you put it back in because it takes awhile for the intake lubrication to work and also it has to go through the crank case and stuff first and also when breaking in two strokes I like to use 16/1 but that's just my own personal thing I don't know about 28/1 I'm sure that would be fine.
I'm no mechanic i just like tinkering. It really sounds to me like the timing is out. It sounds like its pinking to me. Also nowhere nr enough smoke on first start imo. That should've filled your garage. You'll not use too much 2t oil on build! I really hope you've sorted this mate.
I just watched a video of a guy that completely rebuilt a quadzilla. I heard him mention that the bottom end, the case of those engines somehow leak air into the cyclinder and cause it to blow up. Some sort of bearing boss problem is what he says. Look up Johnnie Carter LT500r quadzilla total restoration and see what he has to say about it. Maybe try to talk to him because he sent his engine to someone that actually fixed these issues.
is it a forged piston? they need a bit more clearance as they expand more at operating temperature, maybe check with wiseco about bore size, clearance?? what a bummer, hate when this sort of thing happens. don't give up!!
That fuel petcock might be too small for that motor and not allowing enough fuel to flow . Or the ring end gap was too small and they closed up as it warmed .
When you started it there was no smoke it’s running very lean or piston and rings are out of spec it’s always good to double check your ring end gaps to make sure and weisco is a forged piston specs are different and do leak test check carb boot crank seals etc when you first started it there should be lots of smoke there was literally none I was yelling at my tv to shut it off haha I hope you get it figured out man
Back to square one on this quad. Does anyone know why this would have blown up so quickly?
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was that 2 stroke oil? didnt look like it to me.
Keep up the good work 🔥 you deserve a lot more recognition then you get 💯
Grab some 927 when ur working on older bikes like this best 2 stroke to run ❕🤫
Failure to measure clearances and tolerances
LT250r-500r motors are supposed to have thrust washers one each side between the piston and needle bearing, I would get billet made ones as the factory steel would cause tremendous damage when they came part. Also check the main crank bearings for play, as I have seen that cause the same issue your having.
Leak down test is a must. Honestly! You had the cylinder off along with all the intake components. You could have air being sucked in like crazy around the intake boots. They are notorious for leaking on Suzukis. I have been playing with lt250s for years now and have built plenty motors. I would never consider putting any engine into a frame and starting it after rebuild without first leak testing. I think it was running extremely lean, there was basically no smoke. Almost nonexistent.
Yeah I was wondering that myself about the smoke
@@Chris-ru5eq I've told him over and over and over again about doing leak down tests using proper tools he takes all his bolts out and put some in with an impact driver he takes stuff doesn't drain the gas doesn't drain the oil just trust what someone else has done or trust what someone else has told them if he had took this cylinder and had to measure the clearances for himself before he ever installed it he would not have had this problem not only that but the shop that did the job didn't use torque plates that's why it has scuff marks in the four corners of the piston that's a very common thing when the boar isn't perfectly round if the bike had a ran any longer it would have had a cold seizure he was running factory Jets meanwhile it's bored out it's not big enough where you would consider it a big bore but I have a 421 Cub Banshee and I know all about leak down tests and what can happen if you don't do a leak down test
As soon as it fired i said air leak. Running 28:1 and no smoke out of the exhaust on a 1st start? Shut her down!
Yeah it didn’t even sound right.. could just be the camera and shit but I have built a few zillas in my day and ridden plenty of 500s it did not sound like any zilla I ever heard
@@Chris-ru5eq I know how you feel, I too have commented on his lack of cleanliness (works on filthy engines and carbs) and his "RUclips knowledge" I watch for the laughs and to see how long it takes to blow 'em up. !!
Having the same issue with a Kx85. Couple things to double check Joe
1. Rod bearing
2. Check for grooves in your rod where the wrist pin bearing sits
3. Ring gap
4. You may need a higher flow Petcock
5. Stator side crank seal (could be getting too much air)
6. Timing?
@EleterHD ignition timing
If we're just guessing, id say the small end of the rod is bent, causing the pin to be cocked, causing the piston to sit just a little off in the cylinder. It would explain the tight pin, stuck rings, and the scoring. Just a guess though. Good luck!
Now that's thinking makes sense to me.👍 I'd guess it's probably the case tho same ideeerr
Came here to say something similar but you explained it in a much smarter way😂 but yeah and the fact it happened twice in what looks to be pretty much the same spot.
I think he has damaged the rings letting the piston catch the gasket on the wrong way around then it has blown just a guess 🤔
@@Codyjames83 is there any reason for you to even guess
Would it do any good to bevel that big port out, maybe it's grabbing the piston ring on the up stroke 🤔
At First start I didn't see any smoke, mixed that rich it should have been immediate and thick from the tailpipe. Makes me wonder if the crank seals are bad or needing to be doubled up on one of the sealing gaskets. The scuffs are happening on the exhaust port side so carb tuning wouldn't be the issue. Sorry Joe that's really crappy.
I thought the exact same thing no 2 stroke smoke, she was dry that first minute of run time.
I thought same thing also
Bro if the crank seals were bad they would be pouring oil into the crank case and smoking like a son of a bitch and or pouring oil out the stator side causing a leak condition from the vacuum leak learn what you’re talking about before you comment some shit
@@thegoodjelly4950 depends on what side of the crank it's leaking on IF it's leaking, wet side would make it run rich or possibly leak, coolant side would make it burn coolant and smoke like a chimney, they're all possibilities. Instead of acting a fool, try actually helping without a bad attitude. Don't like it ? There's the door.
Why no smoke on first start?
I appreciate you put a video up that shows us the good and the bad of engine building. Your learning. keep going.
Next time.
Make sure your piston is facing the right direction.
Check your ring gaps
Check piston to wall clearance
Do a leak down.
Wash your cylinder and then wash it again
Make sure you have atleast a film of oil on your cylinder wall and your piston when you assemble
make sure your crank is lubed. And cycle the engine a few times
You can use the 2 stroke oil to lube the parts up before assembly
I definitely think it was an issue with your clearances
Not that this has anything to do with the video or what you said but guys tend to put way too much oil on the piston/rings/ and cylinder and then idle it for 20 hours. They end up glazing the cylinder and the thing doesn’t seat the rings. I’ve seen it happen before and had a dude who had blow by at 10 hours. Cylinder was in spec, rings were in spec. Rebuilt it, rode decently after letting it warm up and then ripped it, no blow by at 40 hours, you need a couple heat cycles if it’s a forged piston though due to the structure of the metal and built up stress that needs to be released as it warms up and expands, and cools down and shrinks.
@@tpghl5225 there is no such thing as over lubing your top end on assembly
@@aaronbright5028 yes there is, over oiling the rings, cylinder, piston etc on a fresh top end can cause issues just as much as too little oil. I’m a small engine service technician, it’s stuff they teach you about lol. I’m not just a RUclips mechanic I do this stuff for a living. A small amount of oil is fine, I wouldn’t start a 2 stroke up completely dry on a fresh rebuild. But just don’t go nuts with it. As well as the heat cycle break in is not necessary at all with a cast piston, I don’t do heat cycles and use cast pistons on my 2 strokes and they make tons of power and last a long time. Never blown a bike up before and I ride pretty hard.
@@tpghl5225 Ive been the head mechanic at 2 different motorcycle dealerships. I became head of shop at 14 when I started and since then I've built every engine from a small block chevy to a cbr954 all the way down to chainsaws and generators. Born and raised in 2 strokes. Out of probably 1200 or more engines I have only had one issue with over lubing and that's smoke on startup. Never fouled a plug never "glazed" my crosshatch. My top ends drip oil from them when I install them. If over oiling was possible I would have found out already man. 15 years experience half at a dealership and I've heard over oiling myths for all of it. Just listen to the dumbasses that think less premix is more power on a 2 stroke and it's completely opposite. But nobody ever tried it they just follow the myths.
@@aaronbright5028 I’m not questioning your seniority at all, I think the main thing comes from idling a fresh motor without much of any change in rpm when these guys do heat cycles especially if the cylinder doesn’t have a fresh hone. Majority of these guys on here in the comments have worn cylinders, don’t own a torque wrench, and never check their ring gap so it’s really the least of their worries either way but my main point in other comments I’ve said on other videos is just letting the bike idle all day long on the first couple startups. This definitely doesn’t seat the rings as would putting some load on it/just riding it. But like I said forged pistons are a different story on the heat cycles as they do need a few, although you still shouldn’t just idle it
At this point a total engine rebuild should be done
In a prior video it was shown that the piston was extending above the cylinder by approximately 2mm at the top of the compression and exhaust strokes so my theory is that the outer circumference of the piston dome is contacting the underside of the head and compressing the ring lands such that the rings are getting stuck and scoring the cylinder. The thermal expansion of the various metals involved once the engine is warmed up while running may exacerbate this condition that may not be evident during the assembly phase of the process while all parts are at room temperature. It is hard to tell in the video, but it looks like there is a witness mark of potential contact on the outer circumference of the piston dome which helps to lead to this theory. Best of luck in diagnosis and repair.
Excellent Kristi, I have a opening in my Race Shop, if you're looking for work in one of the most progressive Motorcycle Engine Building shops in the East coast. I build Turbocharged, Supercharged, and Naturally Aspirated Motorcycle racing engines. I would recommend that you have a TRUE interest in Harley Davidson and Suzuki to be considered. Thank you and I wish you all the very best in your future endeavors.
Ding ding ding, my thoughts exactly, that and not checking quite a few other reasons for the original failure
Get a better compression tester. That one is clearly busted. There’s no way you have 100psi and are nearly standing on top of the kickstarter. Go get a Bosch one from Oreillys
OTC 5605. The best compression tester for $100 or less. Amazon. $94 right now. The snap on one is the same kit in a red box.
Hey there kid . I watch your channel quite often and love your enthusiasm . I'm not going to say my age but I'm an old timer compared to you. I've have worked on just about you name it since I was very young , and have forty years of experience repairing and rebuilding engines . it looked like the piston to wall clearance may have been a bit too tight , and also like you said that the ring gap may be too tight also , the basic rule on ring end gap for just about any engine is .004 per one inch of cylinder bore . so for example with a four inch piston you would want a .016 end gap . especially on a engine that you are going to beat the snot out of because the parts are going to get hot and expand a lot . and also make sure you check the ring side clearance in the ring grooves they look like they might be too tight also, and that will definitely make them seize up and cause scoring , they need proper clearance also to stay lubricated . usually .003 -to .005 . remember that is a big piston so it is definitely going to run hot. . and last but not least make sure and shamfer the edges of the rings when you gap them with a fine file or a whet stone . cause one little burr can make one big groove in your cylinder. and make sure you oil it up well when you assemble everything. I hope a bit of this information helps you out and you complete your mission of your project, Stay safe , have fun , and good luck to you man.
Lean on startup and not nearly enough oil applied to parts when assembled, so it was also a dry start. Should up the pilot and main jet sizes by 5 numbers, initially on a new engine. Will run bad and smoke like crazy, possibly foul plug. But that's the lube that a new 2 stroke needs on initial startup. You didn't check the intake boot for cracks or bad gasket. Possibly bad crank seals. Never checked piston to wall clearance. Never checked ring end gaps. Didn't wash cylinder and piston properly before assembly.
Usually ever machine shop tells u wash cylinder warm soapy water then oil . I'm surprised he didn't.
Piston was out of spec. It happened to me on my 250r. You do get them from time to time. If the wrist pin or the pin hole is out of spec, the piston wont move in the cylinder like it should and then this happens. Tough break but could have been worse. Still fixable relatively cheap. Check the cylinder bore for out of roundness as well.
If nothing else you show many folks what real men do when something goes amiss after a good repair, I for one would have had a temper tantrum but you sir show you can be very disappointed at something and still be calm and push forward. Respect to you and look forward to your repair...
at this point I’d pull the hole motor apart I bet there’s something up with the crank and you should have checked your piston to wall clearance also make sure your rings are in the right orientation
Piston clearance is a must totally agree and richer oil mix for run in just incase
@@backyardbangers1012 RICHER FUEL to Air ratio!
@@glenholmgren1218 that too but more so oil. Dont wanna wash the cylinders bud
You need to do the squish test ONLY in line with the piston pin (sides) so you don't have piston rock giving you a false (& smaller) reading. That's why you had all sorts of different measurements.
What were the piston to cylinder clearances? Looks like it was possibly too tight.
Did the place who bored it chamfer around all the ports? This didn't cause the problem but if it is NOT done, the rings will get eaten fast.
So I noticed when you originally put the cylinder on,that you twisted the cylinder to get it to line up with the base studs.you should never do that because a ring could easily pop out of the Grove if the end gap is in a transfer or exhaust port.buddy of mine had a Honda 250r quad,had to turn or twist the cylinder to line it up,a ring popped out and it rui ed the cylinder and piston. So,if that score in the cylinder lines up with the end gap of a ring,you know what happened.you should always lower the cylinder straight down onto the piston on a 2 stroke,never turn the cylinder after the piston rings are in the cylinder.
Yeah i was looking for this comment and here it is. That's what caused the damage. I know the frame maybe don't have the room for the cylinder to fit in the right way in that case you should remove entire engine to put the cylinder on and then put the engine on the frame.
@@Chris-ru5eq so it was the last video he posted of it,when he put the top end together.and yes,he does find some good machines,I just wish he would listen to some good advice from time to time.usually,I just get smart ass comments from the kids that watch him.worked professionally on bikes quads and snowmobiles for 40 damn years,I know a little bit of what I'm talking about on that stuff.actually had someone tell me the other day that you can put a new chain on old sprockets!!! Lol,that just dont work out!!
@@andrewion88 Exactly!!!
@@Chris-ru5eq seen that!! Hell,He'll, time I just said that a set of impact sockets is cheaper than a hospital visit,and you should have seen the shit storm that it brought on me.little kids telling me I have daddy's money and shit,and I was just trying to look out for him.i try really hard to not comment anymore.
Look at the pipe on the inside where it hooked to the cylinder maybe there carbon build up and it pulled some trash in when you started it ? Did you flush out the bottom end before you did the top end ?
Perhaps the piston contacted the head a couple times causing the ring grooves to clamp onto the rings. Something is not the correct dimension. Piston, rod, bearings or head gasket. I don’t think it ran long enough to cause heat damage due to a possible lean condition. But those intake boot do tend to leak extra air into the engine. I’d check the boot if you do find and repair the problem.
Damaged and squashed the piston and ring grooves by doing all those squish checks (4 times) earlier in video
@@alanparis7256 I was gonna say the same lol should have used putty
@@alanparis7256 I think a piston is to soft to be using solder anyway. I know a lot of people do it that way but I’d be afraid to. It takes a bunch of pressure to mash solder especially with a soft aluminum piston
Was the compression good before it?
The piston pin should move freely, but with some older 2 stroke bike they are very tight!
The piston + rings should not be damaged that quickly! Did you check the piston ring gap?
Another thing that kills pistons that fast is false air. Most of the time its the reedvalve gasket or base basket that causes the problem.
Has the exhaust port been messed with? Has the cylinder been shave?, head shaved?. Measure everything or if in doubt get a completely new top end for it. And jet it super fat and work your way towards the correct mixture
Crank bearing is toast or rod is bent. Crank probably has a lot more play while running then you can realize jus lightly playing with it with your hand
Its either a crank seal or it just wasnt the right piston and ring combo for the build. Regardless of what the measurements seen sometimes it's you have to go with what the engine needs and for running 28:1 I didnt see enough smoke Joe.. it's still running lean somewhere sucking job alot of air
I would investigate the piston ring grove tolerance, have them recut/dressed. sounds like the rings are binding when at running temps possibly.
I’d recommend sending the cylinder and piston to a place like ken O’ Conner racing. Those guys are great and can get you the right piston and clearance the rings correctly. Maybe just send the whole engine in so they can make sure the correct rod was also installed
@Kevin Stearns kinda impossible for some. There’s no one in my area that will do the machining or check specs. So I’m forced to send it off. KOR hasn’t done me wrong
I know this sounds weird to some but I'd use regular ol marine 2 stroke oil. I've been using it since I had started riding 2 stroke. I also work on the road department in PA. We have the demo saws for cutting concrete and other things but the county started supplying us with synthetic blend high performance 2 stroke oil because it was cheaper than the pensoil marine 2 stroke oil we used to use. The saws started seizing up after running for 2 minutes and a few of them blew up. I think the synthetic 2 stroke oil does not lube good enough. Also anytime I blew up a 2 stroke bike the cylinder never had scoring and the rings were never stuck. I also don't see any signs of high heat. Also did you lube the cylinder with 2 stroke oil before you put it back together. Under lubrication will cause the rings to stick. What ever may be wrong I hope you figure it out. Also you could have bent the edge of the piston when you were doing you squish test. Next time you do it try not to get it so close to the edge and make sure it is done in line with the wrist pin.
Since there are two scratches and 2 ring end gaps and the rings are stuck in the ring lands...Most likely the rings were filed to open the gap for spec and the ends weren't beveled. When you file rings you have to file the edges so there isn't a high spot at the end gap.
Yup.
Most likely
Anyone that blips gas before kicking it over on a 2 stroke or always runs bikes with the fuel on "reserve" not "on" like Joe does really needs to find a new hobby. Might wanna try assembly lube when rebuilding and cycle the piston a few times before trying to start it on a fresh top end.
Piston should NEVER be above the cylinder deck. I bet it was tapping the head outside of the squish area. The piston does cock with inertia while running. To me it sounded terrible while idling. Almost like piston to head.
@@devinlawson4093 then you'd see a lot of damage on the head, i had the same when my crankshaft failed and the whole head looks all dented and messed up.
@@devinlawson4093 when he took the engine apart, it looked dry AF. i recommend lubricating everything with 2 stroke oil when assembling.
Good you always giving it a go bro and ta2king the time to upload for everyone. Thankyou bro. I'd check piston clearance first and go from there. And a lil richer on oil mix during break in
Don't you love when quads are this difficult
Always a fun time! haha
But when you get them fix they are hella fun
@@johntrout7572 oh of course
Piston clearance with cylinder wall too tight, did you check ring end gap tolerance before installing them onto piston, ring tolerance can be too tight. Metal expands with heat and needs correct tolerances to run smoothly at running temperatures. Take it to a machine shop and have them assess cylinder bore and what size piston you need. When you fix cylinder and have piston, have the machine shop test the ring end gap and resize, file the ends properly if need be. Hopefully you didn't fubar your connecting rod and crank.
He had a few good comments about checking things like piston to cylinder clearance ring in gap clearance
Wow, so sorry for the lose, but we got faith in you...
Thanks 2Vintage
did you assemble with plenty of oil? rings installed correctly? ring end gap checked? is that a wiseco piston if you had done everything correctly,ball wiseco support.
Perhaps when you did the quench test, maybe you damaged the piston, look like there were quite a bit of force being pushed up on the piston smashing the solder. Just a thought
Supposed to have a piece of solder on both sides of the cylinder. Wasn't done correctly to begin with.
@@specgoos that’s what I thought also but I wasn’t sure. I’m not to up on 2 strokes but I build a lot of four stoke motors
@@specgoos and lined up with the wrist pin.
I was thinking the same thing and I’ve seen several people on RUclips check the squish with solder . It looks like to me that it would put a extreme amount of pressure on new parts. Plumbers putty or play-Doh left in the fridge for a little bit works best
I’ve seen multiple people use solder , it doesn’t hurt the cylinder or piston
I would check the crank/crank bearings after watching the variables in your soldering wires it’s high compression so it’s definitely hard on the rods and crank/crank bearings, you said you put the head gasket on backwards and hit it with the piston, I would’ve probably just replaced it and cleaned the piston of any debris by removing cylinder, Try and drown the piston with 2 stroke oil and let it sit and turn it over slowly to lube everything up before your first start, I have seen guys use putty to find squish clearances to but you would have to take the head off and on to get it out. If you get another new head gasket keep the one that blew up if it’s the same thickness and use the old if “it’s not to screwed up” to find the squish clearances with putty or the plastic squish gauges so your not taking the head off and on with a new gasket messing it up, I’m not a professional so take what I say worth a grain a sand hope you figure it out bud
Quad reminds me of my ex-wife , pour alotta money into something and dont get nothing in return but more headaches 😂😂😂
hahaha
hahahahaah
Spend the time getting the frame back to oem mounts etc, and put a banshee engine back in it.
I’ve owned an 88 quadzilla that rebuild from the ground up elkas/good quality parts etc..it looked beautiful when it was done but it wasn’t what I expected it to be then I bought my first banshee I’ve owned rode it once then sold the quadzilla … the quadzilla has some issues that can’t be corrected… even with elka shocks it handled pretty ruff
Amazing how many things have to go right so nothing goes wrong.
Much respect to your mechanical skills and consistent posting. 🔥💪
Buy a new piston. The cylinder looks like it'll hone out. Then after you get it together buy a cheap leakdown tester off of eBay from South texas banshee. Looks like it was lean causing the piston to melt. Leakdown tester is well worth it.
damn dude you just cant catch a break on this thing
I feel your pain bro I've thrown money at a few projects and they didn't cooperate you'll get it figured out
You need to try and reroute that fuel line away from the exhaust
Smart
Re route it and wrap it with reflective heat tape where it comes close to the carb to. Is there anything in between the exhaust and fuel tank to block heat? I do not think that either one of these were an issue this time it’s got to be something with clearances
@@brandywine1548 no I’m not saying that’s what caused the problem I’m saying get rid of the fuel line away from as much heat is possible just to be on the safe side I say you split cases put a hot rod crank make it a 700 mL port polished ahead put a CP Perillo piston fuck Wiseco get a good set of tires Reeves and redo that motor Charnette plastic back up new seat cover new hand guards it take that down throttle off and put a dirtbike throttle on it and you will have a bike on your hands that everybody is dying to get it
I was thinking this too when I seen that I was like that seems a bit close
Dang. I’ve been waiting so patiently too! Hopefully you get her going again
Hey Joe thanks for the video, I noticed that when you started the bike smoke was not existent. At 28 to 1 there should’ve been quite a bit of smoke especially initially there was zero I’m sure you will go back and watch the video to see this
Use something softer than lead to measure your squish. You would never use a piston to hammer a bit of lead flat on the bench, don't do it in the engine.
Did you install the piston dry? What was your piston ring endgap top and bottom? Always oil the piston and rings prior to install.
Iam doing a full rebuild on a 85 250r motor which was bored to the next available size (66.75). I have just received the new piston first stop for that Is back to the machine shop with the cylinder to confirm clearance is in spec. Iam also doing a new crank and obviously every oil seal and gasket. Before this is fired i will be doing a full leak down test. This way in my opinion will avoid any problems in the near future.
Hey Joe, sorry your going through this , my 2 cents for what its worth , I would run 2 base gaskets ( be prepared for port timing to change ) to relieve that tolerance on the head clearance situation, a bit of work but change crank seals, I also run 40:1 with non oxygenated fuel I all my race bikes aka Can-Am 500 ktm 500 yz490, yz 400 , Husqvarna 500CR , and never a failure under race conditions, most don't know but the thicker you mix your fuel ratio at ( without jetting change ) the leaner your engine will run , double and triple check ring end gap , ps I use Yamabond on all gasket surface since 1985 , best product out there, great video joe 👍 now is the time to dig deep for diagnostic skills , keep up the good fight
There was no issue with head clearance and just like I told the last bean pole crank seals would make the oil leak into the base like hell and it would smoke it’s ass off y’all need to learn how to build a motor
There are two detrimental ring clearances. Rings end gaps people commonly know of. But most don't confirm the ring land clearance. If there isn't enough ring land clearance, as the piston heats up and expands it squeezes the rings and they get stuck. Always ends in disaster. That's what it looked like. I learned the hard way. Also, forged pistons expand more than cast pistons. Forged requires more clearances.
Was any oil used during the assembly ? The components look very dry to me ? ?
Crank seals...it's suckling air somewhere
Are you sure your wrist pin won't go back in the piston? Sometimes they got to go in just right cuz they're such a small amount of clearance. Is there an up and a down to the rings ? What you call a scratch to your cylinder wall I've seen the ring end GAP leave a mark like that in cylinder walls before. Is that actually something you can catch your fingernail in? Did you check compression before you ran it so you had a reference?
My honest thought is the tolerances were to tight piston to cylinder wall clearance
That motor is sucking air somewhere in the crankcase, it will continue to cook pistons until you find the leak. Tear it completely down and find the problem. I've seen 2 stroke engines burn a hole in the piston from sucking air, seems to happen on older snowmobile motors often.
Combine 2 of the most unreliable atvs you get this
You have much more patience than I. I’d have lit it on fire and pushed it off of a cliff if that happened to me.
well.. i don't suspect an air leak as the idle was dropping right back down after releasing. i havent watched the series so not sure how you gapped your rings. not sure how you mixed your fuel with what ratio and oil. how was the crank? in good shape? was the piston installed in correct orientation? what was the piston to cylinder wall clearance? was the cylinder and head nice and level/flat?. other than that. im not to sure. i know how aggravating it is i've had a rm250 like this and a yz80
Metal left in the transfer ports from boring the cylinder that didn't get cleaned out. First time you started it, it sucked all the left over bits of metal that didn't get cleaned out into the cylinder. That's why you have all the scratches on the piston and cylinder and the rings were seized. Top of the piston had oil on it so I doubt it was lack of oil, and you weren't over revving it at all. Not to mention that didn't sound like a seizure when it shut off. Oh and btw, when you're kicking it over, find the hard spot in the stroke and nudge it just past that, then bring the kicker back up and it'll kick over much easier.
are you using an OVERSIDED piston? maybe the box is mislabeled? Its possible once thing heated up they expanded and if you are doing a stock bore with a bigger piston... that's an issue. Check to see if you piston / cylinder clearance is too small.
Thing you need to make sure you never do when installing your cylinder, is make sure it goes on in aliment you never want to spin it left or right as you did. I have a feeling that is why you had this issue.
Yup
I noticed that too.
@@kurtyoung6769 Sometimes it’s a small as shit as a tear of the motor back apart split cases put a hot rod kit in it port and polish the head bore out the jug up to a 700 mL get you a nice CP Perello piston fuck Wiseco make that thing a 700 mL quad banshee Then put a throttle grip like a dirtbike ass and get rid of that dumb shit in new plastic and you’re going to have one hell of a rare motor swell not motorcycle 4Willer on your fucking hands that everybody will want
One other thing you the cylinder may have still had the residue from honing as you only swished it, that I noticed an it will stick your rings.
could be a crap rebore, not perfectly round?. have to be honest i have had hassle both times i have used a wiseco piston ( with running issues) and tend to look for OEM stuff now. not sure both problems you have had with this engine are linked . seems weird the top of piston is oily but piston side is bone dry and has got hot enough to jam the rings up . are both rings identical??? i cant remember with wiseco?
Man, that sucks. Possibly cylinder too tight for the overbore? Did you check that clearance? Ring gap too small? I have my bore guy check those then I check as well.
A few questions, haven't seen all your videos just this one for this banshee. Do you have the tools to measure piston to cylinder clearance? Did you check ring and Gap by putting the rings into the cylinder and checking the Gap with a feeler gauge? I did just buy a set of wiseco banshee Pistons last summer and the ring s in one of the Pistons would stick in the groove so I sent them back and got replacements. I found this before even running it. Just saying could be defective piston.
Nice videos man. Beautiful quad. Keep up the good work
First 45secs no smoke man!
90% sure that’s ring gap/compression issue
@@danielthomas7318 Or jetting....should be up at least 2 on each.
You smashed the rings in the piston from the piston hitting the head it sounds funny like something is nocking probably the piston bro flipping that gasket Will not keep the piston from hitting the head someone shaved the top of the cylinder to raise the ports changing port time it's a really cool mod but you got to put 2 or 3 base gaskets it depends on how thick they are and how much it needs lifted the edge of the piston should be flat with the cylinder and never stick out looked like you already smashed the piston
i saw that it kinda looked like the piston was to high up the cylinder with head off looked like above the top of cylinder im with u on this one this is the cause an when the pison has nowhere to go it bent the pin clamped the rings an compression was lost somehow possibly bending rod but if the pin was bent maybe lucky either way rebuild crank an rod measure everything 50 times lol seals crank bearings must be a measurement for cylinder height get measurement of cylinder yea yyou can do it you must just think like a mathematition
Damn man I feel bad. Was excited to see this thing back rippin
I agree with everyone saying to do a leak test. It was more than likely sucking air in somewhere making it run very lean. There was a very small amount of smoke coming out the exhaust when it was running.
looks like the piston was way to tight in there, did the company where you get your cylinder machined messured the piston clearance and checked it with the original measures? the reason is, if your piston is to tight and it warms up it looks exactly like this and it melts the piston rings on your piston. is it an aluminium cylinder or a metall one? if it is a metall one its even more important to check the clearences for the piston and the rings.
Aluminium and lron both metal, one ferrous one non ferrous
My Englisch is Not that good all ppl how know what they are doing know what i mean ;)
This doesn’t add much value but things that stood out to me was the extreme lack of smoke on start up. It almost looked like a 4 stroke. I wonder if the cooling system is blocked somehow.. it’s odd that it started leaking (possibly from pressure)?
Huge bummer man! I hope you can figure this out for your next startup.
I just picked up a 1981 rm465 that was essentially abandoned. Could’ve been sitting for like 10years. Anyways got it for free. Is it worth refurbishing it? If so what’s the first step? It has compression
IMO I think the ring end gap was too tight. In the last video when you assembled the top end I don't recall seeing you check it. Usually, the ring end gap spec is provided on a little piece of paper in the box with the new piston/rings. Checking it is crucial because if it is too tight the rings will bind as they heat up and expand.
The shop that did the bore triple check that clearance and made sure it was perfect. They even called weisco to ask about it.
@@2vintage it doesn't matter if the shop has done it 15 times when you get it back you double check to make sure because that is 100% the shops failure to do the procedure correctly the other issue that could have happened when they board the cylinder out they may not have had the torque plates if you don't torque the cylinder in between the specs that it's supposed to be clamped down by you can actually have a bore job that isn't round
@@2vintage the fact that the shop had to call wiseco to ask for a clearance that on the instructions in the box of the piston shows their non-knowledge of motors because if boring out cylinders you should know what the clearances need to be I know right off the top of my head what the clearances need to be for every inch of bore
@@2vintage
Why didn't you check the ring gap?
This is how you know.
The cr250 manual says
Ring gap
.016 to .022
Piston to wall clearance
.0024 to .0029.
You check/set ring gap? Rings seem like they were too tight and got cold seized
I've been watching your vids for a while...you've come a long way but the best way to test if a 2 stroke is sealed internally is a leak down test. Even if your carb is jetted correctly if your sucking air in from somewhere it will create a lean condition. I own an 87 lt500r and have rebuilt the top end a few times now and the bottom end once. I'm not sure what happened here but its good to see a nice healthy plume of smoke from 2 stroke exhaust.
Now that I see cylinder ther should be more oil residue. I'm thinking fuel/air/oil issue.
Plume smoke ... Uhhhhhh... I didn't see much .. but ok... If I would fire up my moped on 28:1 I would end mosquitoes on earth ... Yep😐... It's seems to be fubar but I'm not wrench guy... But im the master of blowing shit up.. and yr screwed ..
I do hope you get that Yamaha Banshee running all work you but into it fella feel for ya 👍
Maybe its got the wrong crank for that piston and jug. Or crank is worn. Its nothing to do with the jetting or running lean cause you gotta run an engine lean for a while to cause any damage like that.
The sound I heard when you first started it sounded like a crank of the rod knock and immediately
All the ports inside of cylinder are they completely smooth maybe they haven't been chamford after bore. they can catch onto rings n cause your piston sides to look like that
Man that’s hard to watch man. Thanks for showing problems as well, makes it so much more real.
did you do the rebuilds your self? you generally want to add a generous amount of thick oil around the cylinder and piston rings before you put it back in because it takes awhile for the intake lubrication to work and also it has to go through the crank case and stuff first and also when breaking in two strokes I like to use 16/1 but that's just my own personal thing I don't know about 28/1 I'm sure that would be fine.
There was little to no smoke when starting and running it so it was lean i would consider checking the intake boot for leaks and maybe even a new carb
I'm no mechanic i just like tinkering. It really sounds to me like the timing is out. It sounds like its pinking to me. Also nowhere nr enough smoke on first start imo. That should've filled your garage. You'll not use too much 2t oil on build! I really hope you've sorted this mate.
That oil was super metallic dude!
Looks more like a trx250r. Did you get the new stator in? Would have been fun riding it when we went to the dunes.
The best way to start a Friday! Good stuff man.
I just watched a video of a guy that completely rebuilt a quadzilla. I heard him mention that the bottom end, the case of those engines somehow leak air into the cyclinder and cause it to blow up. Some sort of bearing boss problem is what he says. Look up Johnnie Carter LT500r quadzilla total restoration and see what he has to say about it. Maybe try to talk to him because he sent his engine to someone that actually fixed these issues.
is it a forged piston? they need a bit more clearance as they expand more at operating temperature, maybe check with wiseco about bore size, clearance?? what a bummer, hate when this sort of thing happens. don't give up!!
Is it a forged piston? Duh fucking huh wiseco doesn’t make cast pistons you must be new learn some shit before you comment
Did you have head machined when you did cylinder? You should also use more oil during assembly.
sand and hone and use up to 50:1 mix ratio if it's not smoking add more oil then ride!!! if my 2 stoke doesn't smoke i get worried it might blow up!!
Also remember that more oil will also lean your air/fuel ratio. 28:1 probably a little heavy. I break in and run on 32:1
Lack of smoke when ya first started it for sure. Esp with that mix. Bummer.
tip for next time use electrical solder not plumbing solder
HAVE the cilinder honed, pry out rings and gap 'm right, use 2 basegaskets, mix fuel 50:1 and everything is good.
That fuel petcock might be too small for that motor and not allowing enough fuel to flow . Or the ring end gap was too small and they closed up as it warmed .
Definitely not a fuel issue, would’ve reved to the moon or had an erratic idle etc if it was THAT lean. My bet is the rod is tweaked
I did notice the lack of smoke out the exhaust on start up 🤷♂️
Welcome to the world of 2 strokes😌! That sucks
Dude that thing is a cursed Frankenstein! That yami don’t like engine swap!
Yeah it seriously is haha. Apparently it does not like the swap
I was thinking about this ...what about your water pump maybe it took a dump seems like it got hot possibly since the wrist pin won't fit...
When you started it there was no smoke it’s running very lean or piston and rings are out of spec it’s always good to double check your ring end gaps to make sure and weisco is a forged piston specs are different and do leak test check carb boot crank seals etc when you first started it there should be lots of smoke there was literally none I was yelling at my tv to shut it off haha I hope you get it figured out man
And get rid of that amsoil it’s garbage lol