Yamaha Powersport Forums banner

Yamaha GT 80 Problems

15K views 6 replies 5 participants last post by  Hrevolswer 
#1 · (Edited)
I'm new here and I just purchased A Yamaha GT 80 (i think a 1980) and am having a few problems, wondering if anyone could help?

I got the bike running after a few years via bump starting it as I'm waiting for the kick start spine because it is stripped.

While Driving, the bike jerks alot in the gears, and bogs alot. It is like shaking almost cutting out, but more like clutch slipping or failing? New clutch oil.

Carb was cleaned, never used to idle and it does now. But doesn't want to come out of idle. Does anyone have the STOCK carb settings?

When holding throttle wide open it'll rev up maybe half way for 3-4 seconds, then it will go full out.

I disconnected the oil tank and I'm mixing the gas, but same result.

Just confused and wondering if anyone could help? It would be greatly appreciated.

----EDIT----

Motor Siezed Up
Piston Shattered
Top End Gone
Will Update When Repaired
 
See less See more
#3 · (Edited)
#4 ·
yes it will fit , you will have to have the cylinder bored to the size of the new piston, make sure your piston has the same hole`s in the back of the piston. and have someone inspect your cylinder to see if .50 millimeter will be enough to clean up the cylinder, that way you dont waste your money on a piston that`s not big enough. oversize means it is bigger than the standard size or 47.00 millimeter`s
 
#5 ·
piston and start

ok thanks. i'll get that checked out, but i beleive they are the same pistons.

also, my kick start spine is stripped, so the kickstart wouldn't turn the motor over easily. anyone know where i can get one, otherwise i will drill a vertical whole through the kick and spine and put a bolt through it so it will work full force.
 
#6 · (Edited)
Some links

You can find a copy of the manual's at this link
Inhoud van ./Archief/Yamaha Parts Manuals ALL 1950-1996/GT/

The manual has part numbers that you can search the webs for. So your spline should be easy to find then.

Also a good carb link is here. You might have to open the pictures in new windows, seems like something went wrong.
Is your two-stroke running rich? Read here. - ThumperTalk

Also the pistons can be bored out up to 4 times if you look in the manual. Its best to maybe take it to a yamaha shop and see if they can tell you what size it is. Could see if you need to have it bored after your engined seized as well.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top