This was pretty helpful, looking to rebuild my son's ttr 90 top end as it's lost all compression. Looking for a new piston/standard size or oversized. Any suggestions on where to look for parts?
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
Hey Doc! I know this isn't a big bear 400 video, but i have a question about one, hoping that you can give me an idea where to go with it. I have replaced the cylinder and piston. Had some intermediate smoking, so I replaced the rings with OEM Yamaha brand. Still smoked. Today I replaced the valve guide seals. Still smokes. What could it be man... I'm stuck. Could the guides be so wore that they are letting oil by still?
I'm very seldom see guys or seals let me pull valve. It about has to be the cylinder, when you took the cylinder back apart that was it scratched up the second time?
@@FourwheelerDoctor It had very mild marks in it and I ran my honer on a drill through it before I put the new rings in. This time I didn't inspect the cylinder too well, but it may have had a couple of new scratches in it. What do you recommend now? The cylinder was new, piston new, and rings new. Those cylinder kits are only 90 bucks... should I install another new one?
This was pretty helpful, looking to rebuild my son's ttr 90 top end as it's lost all compression. Looking for a new piston/standard size or oversized. Any suggestions on where to look for parts?
Great Job.
I have a 2007 TTR90 I restored to mint a few Years ago. My Son outgrew it but hard to get rid of. I ride it. Ha
That is going to be very helpful. Thanks for making it
My camshaft chain is not affected by turning the bolt - when setting the timing...... Any thoughts?
What did you bore it to? 47.50?
Yes that is correct
Was there a gasket between the cylinder head and the bottom end?
Yes there was
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
Hey Doc! I know this isn't a big bear 400 video, but i have a question about one, hoping that you can give me an idea where to go with it. I have replaced the cylinder and piston. Had some intermediate smoking, so I replaced the rings with OEM Yamaha brand. Still smoked. Today I replaced the valve guide seals. Still smokes. What could it be man... I'm stuck. Could the guides be so wore that they are letting oil by still?
I'm very seldom see guys or seals let me pull valve. It about has to be the cylinder, when you took the cylinder back apart that was it scratched up the second time?
@@FourwheelerDoctor It had very mild marks in it and I ran my honer on a drill through it before I put the new rings in. This time I didn't inspect the cylinder too well, but it may have had a couple of new scratches in it. What do you recommend now? The cylinder was new, piston new, and rings new. Those cylinder kits are only 90 bucks... should I install another new one?