Has anyone done this? I know that my "75" 400 has a 530 chain. Would there be any advantage to switch to a 520? I was told (but was'nt listening well) there is a difference in the thickness of the counter shaft sprockets (over-all,not the teeth) so it needs shimming, is that correct? Is this another one of my lame ideas? Thanks for any imput. Bob
The 77 GS175 uses 520 chain. I don't know if the countershaft sprocket is interchangeable with the the 250-400 motors. When I get home, I could check the parts manual and see if they will work on either machine.
Rocket
The KTM 520 and 530 sprockets are interchangeable but you should run the same together front and back. Even the 428 sprockets that were first for the KTM 125 will fit the big motors and wheels. DO NOT use them, however. In the past the hot set-up especially on the 400 was the 530. It will last longer and is beefier.