Yamaha TTR90 Top End Rebuild - Part 1 Teardown

[@rhannon86]

Thank you so much for making this video. That helped me so much. It's guys like you that the rest of us look to for help.

[@TheDadBodWorkshop]

Thank you so much for the kind comment! Good luck on your rebuild!

[@tmindek1956]

Where can I find new rings for the ttr90. Looked everywhere they only sell oversize or the 125cc. Please help

[@mc.yohann]

Pretty sure wiseco sells em

[@justindwyer3832]

Hey, I have a ttr90. Has compression first 3 kicks then looses compression. What should I replace?

[@johnkolodzinski8993]

Sounds like the piston rings or valves. Honestly, I would just do a top end rebuild. Safest bet.

[@julianpat6146]

I bought a ttr 90 for 50$ missing a lot engien is seized but the kick start kinda moves idk how much it will be to fix

[@felipegonzalez4403]

Hey I have a ttr 90. Starts good but smokes a lot at all times it’s on. (White) oil through exhaust. What causes that? Thank you.

[@TheDadBodWorkshop]

Very likely valve seals are bad. Does the smoke go away once the engine is warm? Could also be a bad fuel mixture.

[@felipegonzalez4403]

@@TheDadBodWorkshop no it don’t go away. Also is this a 2 or 4 stroke. Just bought the bike yesterday so don’t know to much about it

[@TheDadBodWorkshop]

@@felipegonzalez4403 it is a four stroke engine.

[@jcerrato88]

So im hoping you can help, rebuilt my sons top end but timing chain fell off around the crankshaft. When i shine a light seems like theres two sets of sprockets the timing chain cam go on. Would you by any chance know which one it goes on and best way to get it on? Thanks in advance for any help

[@TheDadBodWorkshop]

The same thing happened to me. Easiest thing is to just take the cover off on the engine block and manually put it back in place. There's only one way the chain can go on. You'll need a new gasket for the cover it you can make one from a paper gasket template. Thanks for watching!

[@jcerrato88]

XinnKoda thanks. Ok ill take the side cover off i think it has 8 bolts or so. So your saying it can only go one way but the two sets of teeth are right next to each other obviously theres one closer to the side cover and one thats closest to the inside of the engine. Just dont wanna end up putting it on the wrong one and it messes up the chain or worse it snaps and comes out of timing

[@TheDadBodWorkshop]

@@jcerrato88 hmm, I don't remember there being two sets of teeth. Seems like once I got the cover off it was pretty obvious how the chain went in. There are guides that should align the chain with how it needs to go. Sorry I can't recall exactly what I did. In either case, you should be able to rotate the engine with the cover still off and make sure the chain isn't getting off track. Let me know what you find out so I can help the next person!

[@otmblok1626]

Aye I have a 2002 ttr 90 Yamaha .. the kicker stuck what could be the problem ?

[@TheDadBodWorkshop]

Will the motor spin over at all? It could be a bent valve, broke timing chain, snapped connecting rod .. lots of things unfortunately.

[@calebbaumgardner8270]

I know this is 4 years later but could you tell me where to get the kit?

[@TheDadBodWorkshop]

I usually get my kits off of eBay. Namura is a brand I've bought from in the past and I've been happy with them. Thanks for watching!

[@calebbaumgardner8270]

@@TheDadBodWorkshop I can't find one for the ttr 90 though

[@calebbaumgardner8270]

@@TheDadBodWorkshop if you could get me a link to one I would be so thankful

[@TheDadBodWorkshop]

www.ebay.com/itm/382052333692?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=TC6Z2KeKQju&sssrc=2349624&ssuid=1soAhdPAQjO&var=&widget_ver=artemis&media=COPY

[@bradymorrison2321]

Where did u find your rebuild kit I cannot find one for my ttr90 at all

[@TheDadBodWorkshop]

Ebay is usually where I find the best deals. Search for TTR90 top end rebuild kit. That should get you in the ballpark. Thanks for watching!

[@bradymorrison2321]

@@TheDadBodWorkshop damn I do man I’ve been searching for months now can’t find anything that I need thanks anyway tho I think it’s bc I need a rings Piston and jug

[@MicRuLerZ]

@@bradymorrison2321 search raptor80 cylinder, piston and gasket kit, they are like $33

[@calebbaumgardner8270]

@@MicRuLerZ thank you so much even though I'm not the one you were replying to I've been looking for a kit so long it's not even funny

[@huntert6452]

On my ttr90, I was riding it one day, the next day I come out to start it, I hear a big snap inside the motor and now it has absolutely no compression, and won’t start what so ever. I’m thinking maybe the timing chain?

[@TheDadBodWorkshop]

That certainly sounds like it could be a timing chain. If it is, you may have gotten really lucky and the chain snapped during the compression phase. Otherwise, the piston would have gone up and hit a valve. Does the engine spin over very easily or is there resistance? Something else you might look into would be the connecting rod. If the rod snapped, the piston won't be moving at all and it would feel very easily spin the engine over by hand.

[@huntert6452]

XinnKoda I can turn the kickstart with my pinky, but I can also hear the suction from the carburetor aswell as the exhaust. I’m kinda stumbled. Also the screws holding on the cover for the timing gear are stripped. I got this bike for free with a clogged carb about a year ago. Only reason why I haven’t gave up on it

[@huntert6452]

XinnKoda hey man! I took the head off and saw that the intake valve was bent

[@huntert6452]

Connecting rod looked good aswell, now I have to order a rebuild kit and a valve and get the timing on point

[@TheDadBodWorkshop]

@@huntert6452 dangit! Hopefully the valve seat didn't get damaged. That's what happened to mine but make sure you correct the timing chain as well. That valve shouldn't have hit unless the problem started with the timing of the engine. I was able to get a slightly used cylinder head off ebay for relatively inexpensive

[@justmintgarage97]

Hey I have been trying to find the 8x1.25 bolt where did you get yours

[@TheDadBodWorkshop]

I bought mine from Ace Hardware here in town but you can also get them online from somewhere like McMaster.com. Thanks for watching!

[@joshowens8738]

I can't find a TTR 90 OR A TTRE 90 TOP END REBUILD KIT PLEASE HELP ONLY FINDING TTR125

[@TheDadBodWorkshop]

Just go to eBay and search for TTR90 Top End Kit.

[@MicRuLerZ]

Try searching for a raptor80 one

[@masonkermicle9534]

“Careful not to ding up the surface or the camshaft” continues to pull cap off new head and bangs the camshaft nice Instructional video though

[@markk7509]

Why didn’t you just remove the gas tank?

[@mudlover4379]

Whats the compression supposed to be

[@TheDadBodWorkshop]

That's a great question. I'm not sure on this engine but usually engines require at least 100 psi. Thanks for warching!

[@nativeohioan4203]

Where can i buy this rebuild kit?

[@TheDadBodWorkshop]

Great question. You can buy kits on eBay that include all your gaskets. If you want to replace everything, you can get a wiseco piston kit which includes most gaskets needed for a top end rebuild

[@douglascasey5550]

XinnKoda I can find one on eBay or anywhere it is all just ttr125

[@danielmarkle8823]

@@douglascasey5550 Did u ever find it because I'm having same problem

[@MicRuLerZ]

@@danielmarkle8823search raptor80 or grizzly80, it uses the same top end parts, only the crank stroke is different

[@danielmarkle8823]

@@MicRuLerZ wow !!! Thanks my friend !!!

[@muhammadnoman5597]

Will you please search Yamaha junoon and look at the engine

[@muhammadnoman5597]

I can also rebuild its top end but I need to know about its transmission and other stuff

[@TheDadBodWorkshop]

Hmm, I haven't rebuilt a transmission in one of these yet but they're pretty simple to work on. They use centrifugal clutches with sequential gear boxes. This one should be pretty straight forward on how to rebuild.

[@muhammadnoman5597]

Hi I have a bike name Yamaha junoon 100cc 4stroke its engine is same to ttr 90 or 110 I want its complete engine rebuild video plz help me with it I am from Pakistan the bike I have is Yamaha junoon or Yamaha 4

[@TheDadBodWorkshop]

I can help you as much as I'm able to. If it's the same engine it should be the same steps as outlined in this video series.

[@fobland3425]

Brother u still active?

[@TheDadBodWorkshop]

More or less. Growing family so I haven't uploaded in a bit. Can I help you?

[@muhammadnoman5597]

Its cylinder number is 102

[@Bickybo]

Those front forks look bent...maybe just a funny camera angle?

[@TheDadBodWorkshop]

They may be bent. I haven't done a detailed inspection on them but it appears to drive just fine. Thanks for watching!

[@justmintgarage97]

Plz help