Its always a good idea to check your valve clearances when replacing a top end but we made another video for adjusting the valves instead of combining it with this one.
Your guys videos are awesome!!!!!! I just put my yfz back together and got it running. Omg. I followed the video step by step. I had it disassembled for about a year. As I've had no extra money to take it to the shop. I just have to fine tune the clutch and carb now and I'm hitting the trails next weekend. Thanks for taking the time to make these videos. Thumbs up!
P.S the shop was charging me $325 to do exactly what part 2 of 2 shows I payed $600 for bottom end work and it was ready to just be put together. Watching another RUclips video I learned how to replace valves and valve springs with household tools. And with this video saved myself $325 in about 2.5 hrs. Thanks.
I just rebuilt my yz450f watching ur tear down and rebuild vids this was the best step by step vid u explain everything and saved me a couple grand subscribed also thank u keep the good vids up
Thanks for the video. It is nice to have a good reference video before I go reassemble my bike. I have a quick note to add for anyone. That air box hooked up to the carb in this video super easy but if yours isn't, spray a little silicone spray on it. Makes the job 10 times easier.
Well directed informational video, for the instructions were to the point and explained so that even guys like me who never worked on a YZ250F could manage this choir of timing the cam to the crank. Thank you for the information.
You may want to check valve clearances and adjust if needed. As for the camshaft Hotcams offers one that includes the auto decompressor and it's listed to fit the 01-13 so that would be a great option
I know they are very similar but Yamaha has made a few changes over the years here and there... If rebuilding your 2004 you could surely follow along with this video and be just fine... Just refer to your service manual for tolerances and specifications
There is no set date on how long any motor will last. Maintenance is what matters so if the oil and air filter have been changed regularly along with other maintenance steps that keep your motor running right. 4 Strokes will go years without needing a rebuild with routine maintenance and being cared for. It's good to inspect your motor to make sure everything is in spec which is done with the help of a service manual. When those things get out of spec you'll know you need adjustment or a rebuild
With upgrading the piston/cylinder with a big bore wouldn't you want to upgrade crank and bearings as well. I put an oem piston/rod in my crf250r and it ended up destroying my crank and bearings. Had to replace everything at that point.
i have an 07 yamaha yz450f and for the timing i have 3 lines side by side on the flywheel which one of those should line up with the mark on the case to indicate that the bike is in top dead center? -jon
@christian johnson You'll have to tear back into the engine to figure out what is causing the kick-starter to bind up. I wouldn't try to kick it anymore or force it to move because you could end up breaking something especially if the timing is off. It could be that a valve is hitting the piston or it could be something jamming up a gear inside. It's hard to say without more information.
hello I bought a wisco piston m series and its a 2004 rmz250 the manual for piston ring gap calls for 15 to 20 I think but in the new piston I bought in the front of the box say 35 or 38 for clearest so is does that mean I need to make my piston ring gap biger to 38 mm and also how would I line up the piston ring
U Va Good morning. I would have you double check your service manual to get the correct piston ring end gap for this particular machine. Ruffly your cylinder's diameter should measure close to 3 inches. Then you would multiply your cylinders bore measurement in inches X .004 and that will give you your piston ring end gap for that particular cylinder bore. If you have any other questions feel free to ask.
Rocky Mountain ATV MC okay because my ring gap in in spec but in the wisco piston I bought its a m series piston in the box say 38 for clearest does that mean the gap between the cylinder and piston not the ring gap and do you guys have a vodeo how line up piston rings thank you
U Va .038mm is referring to the piston to cylinder wall clearance. You're piston ring end gap will be listed inside your service manual so you'll need to refer to that. It will be listed as a minimum ring end gap and in most every case the gaps will be in spec. Here is a video on how to measure ring end gap so be sure that out ruclips.net/video/eeliqbj5DgQ/видео.html Wiseco also provides instructions on lining up your ring ends for installation and this will be the pink paper provided with the piston kit.
+Rocky Mountain ATV MC My wr450f has a 480cc athena big bore kit on it... do I need to get a special gasket from them or can I just buy a normal one from you guys?
Are you sure the rattle is coming from your motor? Does the motor run fine other than that, is it easy to start? It seems like yamaha's tend to make a lot of valve chatter but it could be that something is wrong in the top end. When did you notice this? As for the decompression lever since your bike is not equipped there really isn't any way to start it without pulling the decomp lever. Sometimes you can find aftermarket cams that replace your manual decomp system to auto decomp so check that.
Yes. Your service manual will give the proper orientation of the piston rings. The top piston ring should be stamped with a letter, indicating that it faces up. With the oil scraper piston rings you should refer to your manual. The service manual will give you good detailed instructions on how to install and place these. Thanks
Question...i put my cams back on my head without puting the head on the bike to clean the sealing surface by the valves so that the buckets would not fall out. The cams were tight and would bearly move. I only just snuged the cams caps...? The cams worked fine before i took them off the bike.
rigguyjt Nice catch man! You're right. Rotating the circlips to either 12' or 6' O'clock on the piston will help eliminate any chance of the circlips from popping out. Thats why we like to mention to refer to your service manual for proper piston installation.
At 1:34 of the video, the piston clip is being installed. I will always rotate the clip so that the opening is at 12oclock or 6oclock, as I was once instructed, that at mega high rpm(12k or better) the clip could compress under it's own weight and dislodge if the opening is installed at 3 or 9oclock. Myth or fact? I can say that in 40+ years of turning wrenches and the last 22 years of teaching an Outdoor Powersports program to high school students, a clip has never failed me! Bill Ross Outdoor Powersports Instructor at Maine Region 10 Technical high School
Hey Guys, Great video ... im thinking about a high comp piston (13.5:1) or big bore kit for my 2007 WR450f, I just wanted to know will I still be able to e-start my bike with either of these mods???... Thanks in advance.
Dave Smith Should work just fine with a good charged up battery. It may draw more power from the battery and drain it quicker if you're using it over and over, but it will start the machine.
Thanks for these videos, they're very well done and uber helpful to someone learning the ropes like me. I'm curious why you didn't include a new cam chain in this process. Seems most articles I read say they are prone to break and do a lot of damage, and since they're so cheap to buy it's a wise thing to do. Or are they not considered part of a top end? Thanks.
Yes, that is a very good practice to do changing the cam chain while you're in there. Those articles are correct. We were simply demonstrating the steps to rebuild a top end. I would recommend replacing the cam chain.
I know it's an older video but never rebuilt a dirt bike so was looking into it to rebuild my 04 yz250f. I've rebuilt a few car engines of mine (dsms) and the only thing I noticed bad about your video is using anti seize on the head bolts. antisieze reduces torque which results in lower clamping force of those bolts. this has been test proven many times. to achieve best clamping force from a bolt you use a new bolt with oil, it will be greatly decreased with an old bolt and antisieze. just thought I'd throw this out there whether you use the info or not. I am a mechanic and not trying to be a key board know it all.
enemen8 also another error I saw is when I rebuild the top end I let the oil prime in the lines. (By leaving it the top line unattached) I noticed that it took 30 seconds worth of cranking(when I rebuilt the top end on a TE250) before oil reached the end of the line! (30 seconds without oil!)
What would happen if your oil expander ring were to over lap? I had the hardest time putting the cylinder over the piston and rings. I finally got it on and it goes up and down smooth, but i was having issuses with the oil expander overlapping not sure if it did or not.
Thanks for watching *Min Soo.* Not sure if this will help, but it should give you maybe a better idea on how the transmission is assembled. Give our wide ratio transmission video a look: ruclips.net/video/2wvjipRJ2rI/видео.html . Hope this helps
Hey I just got a 2003 wr450f but I am having an issue. Every once in a while something causes bike to seize? Basically Kickstarter won’t kick anymore. But if I rotate motor through peephole its spins freely. I tore apart the clutch assembly to see all the gears, they all look fine. Everything that I’ve seen so far is good and functioning. Any ideas for the random lockup. Btw it literally happens randomly you can kick it forever and have nothing happen or you can kick it once and it happens. Also when it runs the motor sounds and feels tight (if that makes sense). Please help have no more ideas other than tearing down motor.
My camshaft dots do not line up no matter what I do the left cam (exhaust side) aligns perfect. On the right cam (intake side) the dot either sits above or below the surface of the head. If It will not align straight. Should I go slightly above or slightly below the head surface?
*Jesse The Baldy Ventura* are you installing a new cam chain or the old one? It's best to replace the old cam chain as it may have been possibly stretched, causing the alignment issue? Are your valves shimmed to spec? I would check these things and let us know.. Are you applying pressue with your finger through the cam chain tensioner hole to see where your timing marks will be once the cam chain tensioner will be installed? Try that. See if that fixes what you are seeing.
I have a Yz400f that I replaced all of the gaskets on and timed right during installation . Now, these old bikes have compression levers on them. I went to start and now there is no compression in the motor and my kick moves without holding the lever down. Would you guys have any idea what that may be?
lithium25693 every 50 hours?!?!?! 2 stroke now days last 150 hours in top end if treated good , i buddy of mine has 32k miles on his wr250x and with stock motor
I recently changed the timing chain and tensioner on my 08 yzf250 because the tensioner was defective. The timing was way off and the inside of the muffler was soaked in fuel and smoking just a little, but enough to cause concern. After I got everything reinstalled, cams to tdc and put everything back together, the engine now puffs white smoke. The smoke is pure white, doesn't smell sweet like coolant and it isn't damp. It smells like exhaust and nothing else. Would being off by one tooth on either cam cause this? Or do you think it may be a ring or head gasket? I've ordered new rings and gaskets for it regardless because I was planning a rebuild this winter. The bike will idle without a problem which it wasn't doing before the changes, throttles up without issues either. It is just puffing smoke. I did let the bike idle for about 20 mins to see if it was condensation. The higher the rpms the more smoke would appear. Any suggestions? Great video, thank you for posting that
hi mate my cousin just bourt a 2002 yzf 426 theres water getiing into the oil and theres water getting ontop of the piston and into the exhaust...any sugestionss?hes changet the top head gasket and the water pump seal
Does it matter how long the piston should be, i replaced my old one with a wiseco piston and it has more rings and is a bit longer than the one I had b4
So no crankcase glue on the block or head gaskets? I'm in Indonesia and speak Indonesian so I've been watching all these videos where they load the block and head gaskets with yamabond. I just tore down a 100cc Yamaha mio engine and indeed everything was glued together to the point that I needed to take a grinder and wire wheel to it. I just want to know if that's correct or not to use yamabond on top end gaskets?
You shouldn't need a bigger piston if you hone your cylinder correctly. Honing should just remove glazing and restore the crosshatching, not actually bore the cylinder larger.
Can ask you for something? i have the Yamaha ttr 250 C 1997 and i have a problem with the friction oil seal and i cant fine it. I will send a photo of this and if u can help me... thank you.
Albanian Sniper If you are able to send over a picture I would be happy to help you out no problem. Just not really sure what you are referring to as a friction oil seal? Let me know thanks!
Great video. For me 2:05 was the biggest pain in the ass on the whole job, using a new jug and piston. Getting the rings to compress evenly did not want to happen and it took a long time. It's together now and I'm wondering if I tweaked one of the oil control rings on the bottom slightly because the last OC ring did not slide in smoothly and the bottom of the jug pressed against it, so I am debating whether or not to take the jug back off and put another new set of rings in it to be safe. I am not sure if any ring compressor tool would work with this or not.
thanx , i first noticed the rattle when i was ridding on sand and i had to throttle up to get through, on normal dirt roads i hardly notice it, as for `the cam what year of bike would i have to use to get the auto decomp cam?
Hi , I have one very important question , What kind of motor oil to use after the renovation ? such as commands manufacturer or some special? because it is a new piston and rings, Does it matter?
I would recommend just a general purpose motor oil. Non-synthetic. Then later on you can move to a semi-synthetic or full synthetic. But for the break in period a general purpose engine oil is fine. ~Vinny
I brain farted... on final assembly I used assembly lube rather than motor oil as the lubricant on the piston/rings and the inside of the cylinder. I am still in process... should I disable and clean it all out is the lube innocuous? Thanks a ton for all the help!
There are a lot of mixed opinions on what is better (assembly lube or engine oil) and many people will just stick with what they know. But most assembly lubes are specifically designed to be used on piston skirts/cylinders so you should be more than fine as long as the moving parts are lubed!
i have put my bike back together after reshimming each valve and now my bike has little to no compression and will not start but will occasionally backfire? what have i forgot or what do i need to do? thanks. please help
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Its always a good idea to check your valve clearances when replacing a top end but we made another video for adjusting the valves instead of combining it with this one.
Your guys videos are awesome!!!!!! I just put my yfz back together and got it running. Omg. I followed the video step by step. I had it disassembled for about a year. As I've had no extra money to take it to the shop. I just have to fine tune the clutch and carb now and I'm hitting the trails next weekend. Thanks for taking the time to make these videos. Thumbs up!
P.S the shop was charging me $325 to do exactly what part 2 of 2 shows I payed $600 for bottom end work and it was ready to just be put together. Watching another RUclips video I learned how to replace valves and valve springs with household tools. And with this video saved myself $325 in about 2.5 hrs. Thanks.
streetryderz209 Sweet! Thats what we like to see, glad you got her all back together and running clean! Strong work. Thanks for watching!
streetryderz209 I feel you, man. This video help a ton!! Whenever my top end needs rebuilding, im going to do them myself and save some $$.
probably the best step by step video ive ever seen. Great job
Thanks *Micheal Ortiz* We appreciate it!
Rocky Mountain ATV MC can u email me at RiseWitDaFallen8@gmail.com
I havr a few questions
I just rebuilt my yz450f watching ur tear down and rebuild vids this was the best step by step vid u explain everything and saved me a couple grand subscribed also thank u keep the good vids up
Thanks for the video. It is nice to have a good reference video before I go reassemble my bike. I have a quick note to add for anyone. That air box hooked up to the carb in this video super easy but if yours isn't, spray a little silicone spray on it. Makes the job 10 times easier.
Best produced rebuild video I've seen on the internet. Great work!
I don't even have a dirt bike but I feel like I could work on one now. Excellent informative in depth video!
man! I was hoping you'd start her up at the end! great videos you guys.
It was idling at the end, I think I saw the front wheel vibrating
Well directed informational video, for the instructions were to the point and explained so that even guys like me who never worked on a YZ250F could manage this choir of timing the cam to the crank. Thank you for the information.
+Timothy Kenyon Nice job! Thanks for the feedback
I think this show was alsom now i can do my top end and bottem doing this will save me $500.00 thank u rocky mountain u r bad peace from hawaii.
Clarence Walker Sweet! Thanks for watching and don't forget to subscribe to our channel :)!
You may want to check valve clearances and adjust if needed. As for the camshaft Hotcams offers one that includes the auto decompressor and it's listed to fit the 01-13 so that would be a great option
Big Thanks from Poland for this video!!!! Helping a lot!
you are a blessing for the humanity! Thanks for creating such great explained videos!!
I know they are very similar but Yamaha has made a few changes over the years here and there... If rebuilding your 2004 you could surely follow along with this video and be just fine... Just refer to your service manual for tolerances and specifications
Best explanation video that l ever watched in RUclips!
Great step by step video.
Thank You for this information
*Craig Krage* thanks for chiming in! Glad you liked our video.
Great video. Good detail and clear logical explanation of what you're doing. I've never done thus before, but I think I can now. Thanks a lot.
Glad it helped you out!
Thanks for watching!
There is no set date on how long any motor will last. Maintenance is what matters so if the oil and air filter have been changed regularly along with other maintenance steps that keep your motor running right. 4 Strokes will go years without needing a rebuild with routine maintenance and being cared for. It's good to inspect your motor to make sure everything is in spec which is done with the help of a service manual. When those things get out of spec you'll know you need adjustment or a rebuild
With upgrading the piston/cylinder with a big bore wouldn't you want to upgrade crank and bearings as well. I put an oem piston/rod in my crf250r and it ended up destroying my crank and bearings. Had to replace everything at that point.
i have an 07 yamaha yz450f and for the timing i have 3 lines side by side on the flywheel which one of those should line up with the mark on the case to indicate that the bike is in top dead center?
-jon
it is very similar, but there are differences. Refer to you manual as well.
@christian johnson You'll have to tear back into the engine to figure out what is causing the kick-starter to bind up. I wouldn't try to kick it anymore or force it to move because you could end up breaking something especially if the timing is off. It could be that a valve is hitting the piston or it could be something jamming up a gear inside. It's hard to say without more information.
hello I bought a wisco piston m series and its a 2004 rmz250 the manual for piston ring gap calls for 15 to 20 I think but in the new piston I bought in the front of the box say 35 or 38 for clearest so is does that mean I need to make my piston ring gap biger to 38 mm and also how would I line up the piston ring
U Va Good morning. I would have you double check your service manual to get the correct piston ring end gap for this particular machine. Ruffly your cylinder's diameter should measure close to 3 inches. Then you would multiply your cylinders bore measurement in inches X .004 and that will give you your piston ring end gap for that particular cylinder bore. If you have any other questions feel free to ask.
Rocky Mountain ATV MC okay because my ring gap in in spec but in the wisco piston I bought its a m series piston in the box say 38 for clearest does that mean the gap between the cylinder and piston not the ring gap and do you guys have a vodeo how line up piston rings thank you
U Va .038mm is referring to the piston to cylinder wall clearance. You're piston ring end gap will be listed inside your service manual so you'll need to refer to that. It will be listed as a minimum ring end gap and in most every case the gaps will be in spec. Here is a video on how to measure ring end gap so be sure that out ruclips.net/video/eeliqbj5DgQ/видео.html Wiseco also provides instructions on lining up your ring ends for installation and this will be the pink paper provided with the piston kit.
+Rocky Mountain ATV MC My wr450f has a 480cc athena big bore kit on it... do I need to get a
special gasket from them or can I just buy a normal one from you guys?
Are you sure the rattle is coming from your motor? Does the motor run fine other than that, is it easy to start? It seems like yamaha's tend to make a lot of valve chatter but it could be that something is wrong in the top end. When did you notice this? As for the decompression lever since your bike is not equipped there really isn't any way to start it without pulling the decomp lever. Sometimes you can find aftermarket cams that replace your manual decomp system to auto decomp so check that.
Does it matter about which way the rings go in?
Yes. Your service manual will give the proper orientation of the piston rings. The top piston ring should be stamped with a letter, indicating that it faces up. With the oil scraper piston rings you should refer to your manual. The service manual will give you good detailed instructions on how to install and place these. Thanks
great video! While you're at it, remember to install a new spark plug too ;)
Question...i put my cams back on my head without puting the head on the bike to clean the sealing surface by the valves so that the buckets would not fall out. The cams were tight and would bearly move. I only just snuged the cams caps...? The cams worked fine before i took them off the bike.
Great vid....I'm thinking about buying a 4stroke and wondered how everything went together! lol- nice work thanks guys!
You Bet! Thanks for the quick tip!
Thanks Nick!
You forgot to mention the surclip openings on the piston should be at 6 o clock or centrifugal force can pop them out into your cylinder.
rigguyjt Nice catch man! You're right. Rotating the circlips to either 12' or 6' O'clock on the piston will help eliminate any chance of the circlips from popping out. Thats why we like to mention to refer to your service manual for proper piston installation.
At 1:34 of the video, the piston clip is being installed. I will always rotate the clip so that the opening is at 12oclock or 6oclock, as I was once instructed, that at mega high rpm(12k or better) the clip could compress under it's own weight and dislodge if the opening is installed at 3 or 9oclock. Myth or fact? I can say that in 40+ years of turning wrenches and the last 22 years of teaching an Outdoor Powersports program to high school students, a clip has never failed me! Bill Ross Outdoor Powersports Instructor at Maine Region 10 Technical high School
Hey Guys, Great video ... im thinking about a high comp piston (13.5:1) or big bore kit for my 2007 WR450f, I just wanted to know will I still be able to e-start my bike with either of these mods???... Thanks in advance.
Dave Smith Should work just fine with a good charged up battery. It may draw more power from the battery and drain it quicker if you're using it over and over, but it will start the machine.
What oil are you using, just the same oil you normally put in the bike whatever synthetic you use?
Thanks for these videos, they're very well done and uber helpful to someone learning the ropes like me. I'm curious why you didn't include a new cam chain in this process. Seems most articles I read say they are prone to break and do a lot of damage, and since they're so cheap to buy it's a wise thing to do. Or are they not considered part of a top end? Thanks.
Yes, that is a very good practice to do changing the cam chain while you're in there. Those articles are correct. We were simply demonstrating the steps to rebuild a top end. I would recommend replacing the cam chain.
(
Actually we didn't drain the oil out of this motor when we rebuilt it so we didn't have to refill, great catch though!
very helpful vid thanks for sharing ur knowledge, can u make a vid how to increase hp??? will be awesome hope to see it soon
I know it's an older video but never rebuilt a dirt bike so was looking into it to rebuild my 04 yz250f. I've rebuilt a few car engines of mine (dsms) and the only thing I noticed bad about your video is using anti seize on the head bolts. antisieze reduces torque which results in lower clamping force of those bolts. this has been test proven many times. to achieve best clamping force from a bolt you use a new bolt with oil, it will be greatly decreased with an old bolt and antisieze. just thought I'd throw this out there whether you use the info or not. I am a mechanic and not trying to be a key board know it all.
enemen8 also another error I saw is when I rebuild the top end I let the oil prime in the lines. (By leaving it the top line unattached) I noticed that it took 30 seconds worth of cranking(when I rebuilt the top end on a TE250) before oil reached the end of the line! (30 seconds without oil!)
@@xtune5731 That's what the assembly lube is for. Initial lubrication until the oil supply reaches the bearings.
What would happen if your oil expander ring were to over lap? I had the hardest time putting the cylinder over the piston and rings. I finally got it on and it goes up and down smooth, but i was having issuses with the oil expander overlapping not sure if it did or not.
well put together guys... thank you!!!!
Thanks buddy.
Can u do a complete ttr 230 rebuild video
Nice video ! seriuosly all explain in detail. i wish that next time if you do the gear box rebuild too^^
Thanks for watching *Min Soo.* Not sure if this will help, but it should give you maybe a better idea on how the transmission is assembled. Give our wide ratio transmission video a look: ruclips.net/video/2wvjipRJ2rI/видео.html . Hope this helps
Thank you so much, i really appreciate it. Thumb up and subscribed for you!!!!
Brilliant job
Thank you!
I was thinking of doing the cylinder works 270 big bore kit on my WR. I was wondering if you had to rejet your carb after the big bore install?
Watch this video as he puts anti sieze on bolts it changes torque value
+Christina Neasloss ohhhhhhhhhhh shiiit them fighting words
Very nice video and professional work
thanks!
After watching this video it reminds me why I like me a 2 stroke lol
Hey I just got a 2003 wr450f but I am having an issue. Every once in a while something causes bike to seize? Basically Kickstarter won’t kick anymore. But if I rotate motor through peephole its spins freely. I tore apart the clutch assembly to see all the gears, they all look fine. Everything that I’ve seen so far is good and functioning. Any ideas for the random lockup. Btw it literally happens randomly you can kick it forever and have nothing happen or you can kick it once and it happens. Also when it runs the motor sounds and feels tight (if that makes sense). Please help have no more ideas other than tearing down motor.
What kind of oil are you using when lubricating everything?
Any chance you re doing a video like this with a newer fuel injected bike?
can you use gaskets again if bike hasn't been started?payed 100£ and had transmition issues and had to strip
why do you put anti-seize on the head bolts? doesn't that affect the torquing of them?
Your surclips looked like they were at 3 o clock which could compress under force out when running. byebye cylinder.
My camshaft dots do not line up no matter what I do the left cam (exhaust side) aligns perfect. On the right cam (intake side) the dot either sits above or below the surface of the head. If It will not align straight. Should I go slightly above or slightly below the head surface?
*Jesse The Baldy Ventura* are you installing a new cam chain or the old one? It's best to replace the old cam chain as it may have been possibly stretched, causing the alignment issue? Are your valves shimmed to spec? I would check these things and let us know.. Are you applying pressue with your finger through the cam chain tensioner hole to see where your timing marks will be once the cam chain tensioner will be installed? Try that. See if that fixes what you are seeing.
Thanks for the videos guys!
What about the valve adjustment?
Del Emerson i was wondering the same thing...
Del Emerson You can check out our Valve Adjustment video here: ruclips.net/video/1lrH1U4FnRY/видео.html
racequad9 You can check out our Valve Adjustment video here: ruclips.net/video/1lrH1U4FnRY/видео.html
How many pounds are given to screws holding the head and cylinder?
What torque setting did you use on head bolts and cam covers when you reassembled it all?
Hi good vid can you do a full engine rebuild on wr250f please
I have a Yz400f that I replaced all of the gaskets on and timed right during installation . Now, these old bikes have compression levers on them. I went to start and now there is no compression in the motor and my kick moves without holding the lever down. Would you guys have any idea what that may be?
Hi, great vid. I’ve a wr450f to do the same too, apart from torque settings , piston sizes etc... would it be basically the same layout to do ? Cheers
How often do you need to rebuild the motor?
Every ride
A 4 stroke dosent need rebuild unless damaged , i has around 13,000-15,000 on a yz250f i recently sold , still ran perfect
A 4 stroke top ends needs to be replaced every 50 hours
lithium25693 every 50 hours?!?!?! 2 stroke now days last 150 hours in top end if treated good , i buddy of mine has 32k miles on his wr250x and with stock motor
I'm referring to a yz250 motocross bike a wr250x will last a lot longer than a yz250
Hey looked like you reused your head bolts? Thought you had to replace them? Because they stretch?
I recently changed the timing chain and tensioner on my 08 yzf250 because the tensioner was defective. The timing was way off and the inside of the muffler was soaked in fuel and smoking just a little, but enough to cause concern. After I got everything reinstalled, cams to tdc and put everything back together, the engine now puffs white smoke. The smoke is pure white, doesn't smell sweet like coolant and it isn't damp. It smells like exhaust and nothing else.
Would being off by one tooth on either cam cause this? Or do you think it may be a ring or head gasket?
I've ordered new rings and gaskets for it regardless because I was planning a rebuild this winter.
The bike will idle without a problem which it wasn't doing before the changes, throttles up without issues either. It is just puffing smoke. I did let the bike idle for about 20 mins to see if it was condensation. The higher the rpms the more smoke would appear.
Any suggestions?
Great video, thank you for posting that
Can the timing chain fall off the crank if it looses tension?
Can I get these rocky mountain kits in New Zealand need a top end
hi mate my cousin just bourt a 2002 yzf 426 theres water getiing into the oil and theres water getting ontop of the piston and into the exhaust...any sugestionss?hes changet the top head gasket and the water pump seal
if you are double checking the torque you are over torquing the bolts FYI
Good job i like what i see👌🏾👍🏾
Can you use car coolering at dirtbike
Would this guide apply to a YZ426F?
Does it matter how long the piston should be, i replaced my old one with a wiseco piston and it has more rings and is a bit longer than the one I had b4
Some aftermarket pistons will be a bit different than the stock one but I would confirm the part number you received is the correct one for your bike.
As always great video , Thanks!!
So no crankcase glue on the block or head gaskets? I'm in Indonesia and speak Indonesian so I've been watching all these videos where they load the block and head gaskets with yamabond.
I just tore down a 100cc Yamaha mio engine and indeed everything was glued together to the point that I needed to take a grinder and wire wheel to it.
I just want to know if that's correct or not to use yamabond on top end gaskets?
Good question. No, you don't need glue/Yamabond on the the base or head gasket.
Do you need to buy a bigger piston when you home the cylinder?
You shouldn't need a bigger piston if you hone your cylinder correctly. Honing should just remove glazing and restore the crosshatching, not actually bore the cylinder larger.
Nice and Clean Job Man...
Albanian Sniper Hey thanks! Glad you enjoyed.
Can ask you for something? i have the Yamaha ttr 250 C 1997 and i have a problem with the friction oil seal and i cant fine it. I will send a photo of this and if u can help me... thank you.
Albanian Sniper If you are able to send over a picture I would be happy to help you out no problem. Just not really sure what you are referring to as a friction oil seal? Let me know thanks!
Great video. For me 2:05 was the biggest pain in the ass on the whole job, using a new jug and piston. Getting the rings to compress evenly did not want to happen and it took a long time. It's together now and I'm wondering if I tweaked one of the oil control rings on the bottom slightly because the last OC ring did not slide in smoothly and the bottom of the jug pressed against it, so I am debating whether or not to take the jug back off and put another new set of rings in it to be safe.
I am not sure if any ring compressor tool would work with this or not.
How'd it go?
@@ZmannR2 ended up fine just one of those things that was new to me. it ran really well.
thanx , i first noticed the rattle when i was ridding on sand and i had to throttle up to get through, on normal dirt roads i hardly notice it, as for `the cam what year of bike would i have to use to get the auto decomp cam?
Will this work for a 2017 wr250f?
What kind of oil did you use to lube the cylinder and piston?!?!?!
Any all purpose 4 stroke motor oil will work. Preferrably a non synthetic for the breaking in part.
Hi , I have one very important question , What kind of motor oil to use after the renovation ? such as commands manufacturer or some special? because it is a new piston and rings, Does it matter?
I would recommend just a general purpose motor oil. Non-synthetic. Then later on you can move to a semi-synthetic or full synthetic. But for the break in period a general purpose engine oil is fine. ~Vinny
awesome job man that's a great video.
I brain farted... on final assembly I used assembly lube rather than motor oil as the lubricant on the piston/rings and the inside of the cylinder. I am still in process... should I disable and clean it all out is the lube innocuous? Thanks a ton for all the help!
There are a lot of mixed opinions on what is better (assembly lube or engine oil) and many people will just stick with what they know. But most assembly lubes are specifically designed to be used on piston skirts/cylinders so you should be more than fine as long as the moving parts are lubed!
Is this the same for an ATV? Like a 2014 Raptor 700R?
+wolfpackflt670 Very similar yes.. you would see some different moving parts of course, but same process
+Rocky Mountain ATV MC it sames like all 4 stroke are closely thesame
i have put my bike back together after reshimming each valve and now my bike has little to no compression and will not start but will occasionally backfire? what have i forgot or what do i need to do? thanks. please help
With the bike back together are the valves still within spec? That's the first thing i would check and if they are i would check your timing next
i don't have dots in my camshafts wt should i do , thereis only two E
For some reason my valve cover is leaking on my yz250f 2015 plz help
Where can I find torque specs or an online yamaha service manual?
how long do you recomend you let the silicone set for before starting the bike ?
The instructions on the silicone tube should say at least an hour.
Same concept for Raptor 700 engine?
What marking is TDC on the flywheel? I’ve been told it’s the letter “I” but also told it’s the dot?
Did you ever figure out which one it is?
is there a certain way the cams go into the head
Is it not usual to replace valve stem seals when a top end is overhauled?
For a high-mileage engine yes, but he was just installing a big-bore kit, not overhauling.
How do you tell if its at TDC on compression stroke or 180º out?
Intake cam lobes will be just off the valve caps and rotating away for the next revolution.
thankyou justin
ya you are at the right place.
Excellent
how many power use in
Torque wrench?
very nice video but i don't have Motorcycle but was a good video
lol