76' 125 Chain Size

[Chakka]

I need to order some sprockets and chain for my 76' KTM engined 125. Does anybody know how many links I will need and it it a 520 or 530 chain?

Chakka

[Mike Lenz]

I would run a 520 or 428 chain. I just go with 120 links with 520 chains and cut them to size.

[Chakka]

Thanks Mike...I measured the rear sprocket and your right...it has to be set up for 520. I will order them tomorrow.

Chakka

[rob w]

Originally it uses a 428 chain. A good quality 428 chain today appears to be made better than the old days. I use a 428 on mine.
520 seems like over-kill on a vintage 125. Yes , No....?

[john durrill]

Rob,
 I think your right. The new 428 is very strong chain. Less mass than a 525 or even the 520. That would be better for 125. The 77 parts book we have shows both the 125 and the 175 engines use the same size / part # sprocket though. The 125/175 counter sprockets are the same as the LC4 KTM 4 stroke in spline and shaft size but you have to fit a spacer behind the sprocket to line things up right. Sprocket Specialist or Barry Higgins  could supply the counter shaft sprockets in 520 I think.
 Did KTM offer the smaller chain for the 125 later?
John D.