82 tt250

[hdw75]

Hi there
I'm after some mechanical info on the tt250 early 80s bikes, I went to put a new chain on my recently acquired TT but when I removed the front sprocket for cleaning I found that the counter shaft spline teeth were chewed up with a very sloppy fit for the sprocket. So any one know how involved it is to replace the counter shaft??? Any help appreciated .
Also looking for parts for this bike does anyone have a motor in bits they want to part ?
Cheers

[Dave89]

they have vertical split crankcases, so its a complete engine strip to change the output shaft, i seem to remember back in the day we either where able to buy a sprocket with a thicker centre ( from another model by trawling through jt sprockets catalogue), therefore making more contact with the shaft and a part of the shaft that is not worn out, or we made a wider one buy welding the centre of an old sprocket to the back of the new one.

[pete-blen]

they were a bit of crap in 1982... can't imagine
they have got any better with age....
before yer spend any $ on it... have a look at
the cam & bearing surfaces / rocker arms / cam lobes etc
they were there biggest issue,,not there only one
but there biggest...

Any big $ spent on a TT250 is $ wasted...

I bought mine new & killed it in 4 months... peice of crap....
yamaha fixed it... then traded it on a IT465....




.

[hdw75]

they have vertical split crankcases, so its a complete engine strip to change the output shaft, i seem to remember back in the day we either where able to buy a sprocket with a thicker centre ( from another model by trawling through jt sprockets catalogue), therefore making more contact with the shaft and a part of the shaft that is not worn out, or we made a wider one buy welding the centre of an old sprocket to the back of the new one.

Thanks for the tips , might try the welding method as its only worn down the first 10mm from the retainer clip, as for spending too much $ on it I only paid 660 for it and it has a recon motor , I'm aware of the worn camshaft rocker issues , luckily I got a replacement cam and rockers cheap off trade me plus I do mine own work on it so hopefully won't spend too much.
Done some reading up on the oil starvation problems on the top end ,apparently the yamaha fix was a specific sized roll pin in the end of the crankshaft does anyone have any experience with this?
If there's any old TT owners out there that like these bikes check out this linkhttp://phillittleracing.com/motorcycle/phils-toys/yamaha-tt250-trail-bike