FYI I don't make any money off these links. I bought this stuff myself. This is the complete Top End Kit that I used. velocitytitan.com/products/1986-1987-honda-trx70-top-end-rebuild-kit-cylinder-head-piston-generic READ the video description. I talk more about it there. Athena Gasket kit www.ebay.com/itm/314956921308 READ the video description. I talk more about it there. FULL TRX-70 REBUILD PLAYLIST HERE ruclips.net/video/OmHnUkPvwAM/видео.html #Doitforcolton
Thanks for the insight. I just got a 1987 fourtrax 70 for my son that needs a top end. Just ordered the same kit you used. It’s been garage kept and in really good shape. It was running good but smoked(to be expected) so I’m hoping the full top end will take care of it. Just another 80’s model Honda to add to my fleet and experience for my son. Thanks again!
Crazy. I’ve watched the build series for this Honda on your other channel a bunch of times. I’m restoring my childhood 86 trx70 for my 5 year old right now too.
This brought back a lot of memories for me and I'm sure it will you too, plus whatever you spend on the build, your still going to come put on top. The 85 and 86 fetch big bucks if they are in good shape. We will probably end up giving this to our grandkids, kids, someday.
Thanks man! I'm just glad it's finally right lol. It was getting very frustrating and costly at 40 a pop every time I pulled it apart to replace head and base gasket
One thing we used to do with 4 stroke engines after strip down is used 2 stroke oil for the 1st tank full of fuel. Seemed to make them bed in better. 50 - 100 to one. Thanks for posting.
One thing i learned a long time ago is after valves are installed, use a wood dowel ass a punch and pop the valve stem a couple of times to be sure the locks and springs settle in place before installing rockers.
What about buying a 90cc big bore kit - ? What big bore kit would you recommend for "Easy Bolt-on" without changing the carb out (maybe just a bigger jet for the carb). Thanks
I'm not a big fan of those big bore kits for one of the reasons you mentioned because it causes rejetting and carburator adjustments, not to mention that I think big bore kits reduce overall reliability because of the additional rotating mass..
The Athena gasket kit did NOT have that rectangular seal but the stock honda gasket did. It smoked using both styles. I even thought it was the weird bushing at oil pump.area that gets the o-ring and even with OEM gaskets and seals it was still blowing smoke. I'm thinking the domed piston must have kissed one of the stock valves. I can't think of any other reason.
Just wondering? Did you hone the cylinder so the new ring can be broken in. If not that may be why it was smoking after. Unless it smoked before the rebuild. Then who knows.
The first cylinder i did not hone because it was new and had already been done. After that one smoked, I took my original cylinder and gave it a light hone with the new piston and rings and that one now smoked also. I learned that the 1st cylinder had excess clearance so I sent it back and when it returned it still smoked. It wasn't until I bought the complete kit in the link that it fixed everything.
Did add the all o-ring to head gasket side one of which is for oil feed up to head to feed rocker shaft and cam journal as it may force oil into the combustion chamber if it missing and make sure the first and second ring gap facing towards the bottom one clock at 4 and other at clock at 7 that oil can drain off and not pool up In between the rings and oil ring gap at clock at 12.
I think something in the head failed because I put it together the same way all 5 times..I even oriented the rings as shown in the manual. As soon as I got the new kit, it worked no problem. Weird.
@@MotoVated207 Then the only other thing I can think of was something and was out around this could possibly be a cylinder itself and when you installed new rings they were round but they weren't truly round to match the cylinder wall so therefore you ended up with an oblong shape cylinder that is why it is so important to used correct type of home procedure to do this not a three prong or a ball hone It would have revealed this right away, there are other possibilities but you have to really know what you're looking for when it comes to the rings and piston that you have bought especially some clone models by the way I was just curious did you measure the piston wall clarence this can create a problem to if there is too much clearances. Oh yes the more modern heads are much better especially with roller bearing cam however if I would have built this I would have gone with 88cc kit the nice upgrade and nice thing about your TRX it is essentially just a ATC 70 frame with 4 wheels Instead of 3. year ago I drop in 110 Electric start in our ATV 70 boy what blaste it was I wish the Daytona 190 was out that would rock but I'm sure I would have had this stretch to frame up you inches and make it fit
@SHSPVR it was a brand new cylinder, piston and rings that I bought as a complete assembly supposedly from a company that builds pistons and cylinders for Honda. I mic'd everything and found out the piston to cylinder was .003 and sent it back. They bored the new cylinder .025 and sent it back with a new piston and rings and it still smoked. Meanwhile I'm buying gasket kits like it was a job and I bought a second top end kit from a different source that also included a complete head with valves, cam complete and this immediately solved the smoking problem. I never did figure out why. The only thing I can think of, there is an O ring under the valve guide. I didn't push out the guides because the valves didn't seem to have an issue other than possible leaky valve seals. I'm still puzzled.
@@MotoVated207 Then it can only be two possible causes this piston and rings or a worn out intake valve guide and valve stem as it was able to suck the oil from the top end on the intake stroke even with new seal and the exhaust valve side if worn out will usually be small or large amount of white smoke at startup only but goes away after a minute something but this will always be consistent at startup that's usually that a good sign of a bad valve seal as it leak pass the seal. Oh, that not good at .003 between the cylinder walls when should been roughly round .0003 to .0005 on a fresh bore cylinder to piston by the way a good place to find TRX parts is called dratv if you haven't already run a cross it, PS you really good job with the restoration👍.
FYI I don't make any money off these links. I bought this stuff myself. This is the complete Top End Kit that I used. velocitytitan.com/products/1986-1987-honda-trx70-top-end-rebuild-kit-cylinder-head-piston-generic READ the video description. I talk more about it there.
Athena Gasket kit www.ebay.com/itm/314956921308 READ the video description. I talk more about it there.
FULL TRX-70 REBUILD PLAYLIST HERE ruclips.net/video/OmHnUkPvwAM/видео.html
#Doitforcolton
Thanks for the insight. I just got a 1987 fourtrax 70 for my son that needs a top end. Just ordered the same kit you used. It’s been garage kept and in really good shape. It was running good but smoked(to be expected) so I’m hoping the full top end will take care of it. Just another 80’s model Honda to add to my fleet and experience for my son. Thanks again!
Excellent! He will enjoy it and the Honda legacy lives on! Nice job dad!
Crazy. I’ve watched the build series for this Honda on your other channel a bunch of times. I’m restoring my childhood 86 trx70 for my 5 year old right now too.
This brought back a lot of memories for me and I'm sure it will you too, plus whatever you spend on the build, your still going to come put on top. The 85 and 86 fetch big bucks if they are in good shape. We will probably end up giving this to our grandkids, kids, someday.
@@MotoVated207 cheers, from a fellow Mainer!
Great show of persistence, Brandon! Cool vid!
Thanks man! I'm just glad it's finally right lol. It was getting very frustrating and costly at 40 a pop every time I pulled it apart to replace head and base gasket
One thing we used to do with 4 stroke engines after strip down is used 2 stroke oil for the 1st tank full of fuel. Seemed to make them bed in better. 50 - 100 to one.
Thanks for posting.
Awesome suggestion! I will be doing this!
I pulled apart and rebuilt a harbor freight predator 212cc engine a couple years back and it was surprisingly easy. Really fun learning how it worked.
I did my wife's honda a couple weeks ago and it was the same process as this. I think the head is messed up.
Glad you got it fixed properly and it should last many years
I'm so glad it's fixed. I was getting a little worried
One thing i learned a long time ago is after valves are installed, use a wood dowel ass a punch and pop the valve stem a couple of times to be sure the locks and springs settle in place before installing rockers.
Thats actually a great idea. Then you don't have to wonder if your keepers are seated properly. Thanks for sharing 👍
Congratulations on the new grand baby!
Thank you Scott!
What about buying a 90cc big bore kit - ? What big bore kit would you recommend for "Easy Bolt-on" without changing the carb out (maybe just a bigger jet for the carb). Thanks
I'm not a big fan of those big bore kits for one of the reasons you mentioned because it causes rejetting and carburator adjustments, not to mention that I think big bore kits reduce overall reliability because of the additional rotating mass..
So with your new cylinder/cylinder head gasket, did it have the cam seal chamber rubber rectangular seal? Or do the newer gaskets not need it?
The Athena gasket kit did NOT have that rectangular seal but the stock honda gasket did. It smoked using both styles. I even thought it was the weird bushing at oil pump.area that gets the o-ring and even with OEM gaskets and seals it was still blowing smoke. I'm thinking the domed piston must have kissed one of the stock valves. I can't think of any other reason.
Just wondering? Did you hone the cylinder so the new ring can be broken in. If not that may be why it was smoking after. Unless it smoked before the rebuild. Then who knows.
The first cylinder i did not hone because it was new and had already been done. After that one smoked, I took my original cylinder and gave it a light hone with the new piston and rings and that one now smoked also. I learned that the 1st cylinder had excess clearance so I sent it back and when it returned it still smoked. It wasn't until I bought the complete kit in the link that it fixed everything.
Did add the all o-ring to head gasket side one of which is for oil feed up to head to feed rocker shaft and cam journal as it may force oil into the combustion chamber if it missing and make sure the first and second ring gap facing towards the bottom one clock at 4 and other at clock at 7 that oil can drain off and not pool up In between the rings and oil ring gap at clock at 12.
I think something in the head failed because I put it together the same way all 5 times..I even oriented the rings as shown in the manual. As soon as I got the new kit, it worked no problem. Weird.
@@MotoVated207 Then the only other thing I can think of was something and was out around this could possibly be a cylinder itself and when you installed new rings they were round but they weren't truly round to match the cylinder wall so therefore you ended up with an oblong shape cylinder that is why it is so important to used correct type of home procedure to do this not a three prong or a ball hone It would have revealed this right away, there are other possibilities but you have to really know what you're looking for when it comes to the rings and piston that you have bought especially some clone models by the way I was just curious did you measure the piston wall clarence this can create a problem to if there is too much clearances. Oh yes the more modern heads are much better especially with roller bearing cam however if I would have built this I would have gone with 88cc kit the nice upgrade and nice thing about your TRX it is essentially just a ATC 70 frame with 4 wheels Instead of 3. year ago I drop in 110 Electric start in our ATV 70 boy what blaste it was I wish the Daytona 190 was out that would rock but I'm sure I would have had this stretch to frame up you inches and make it fit
@SHSPVR it was a brand new cylinder, piston and rings that I bought as a complete assembly supposedly from a company that builds pistons and cylinders for Honda. I mic'd everything and found out the piston to cylinder was .003 and sent it back. They bored the new cylinder .025 and sent it back with a new piston and rings and it still smoked. Meanwhile I'm buying gasket kits like it was a job and I bought a second top end kit from a different source that also included a complete head with valves, cam complete and this immediately solved the smoking problem. I never did figure out why. The only thing I can think of, there is an O ring under the valve guide. I didn't push out the guides because the valves didn't seem to have an issue other than possible leaky valve seals. I'm still puzzled.
@@MotoVated207 Then it can only be two possible causes this piston and rings or a worn out intake valve guide and valve stem as it was able to suck the oil from the top end on the intake stroke even with new seal and the exhaust valve side if worn out will usually be small or large amount of white smoke at startup only but goes away after a minute something but this will always be consistent at startup that's usually that a good sign of a bad valve seal as it leak pass the seal. Oh, that not good at .003 between the cylinder walls when should been roughly round .0003 to .0005 on a fresh bore cylinder to piston by the way a good place to find TRX parts is called dratv if you haven't already run a cross it, PS you really good job with the restoration👍.
Thank you 👍
What valve tools did you use?
I think it was just just a basic spring compressor kit I got online.
Go power sports sells all kinds of upgrades for these small engines.
I'll have to check them out. Thanks! Good to hear from you also. I hope all is well.
you are a mechanic.
Nah, I just enjoy wrenching. I don't do this for a living. It's a hobby.