[ducxl]

a friend has a ratty '99 996s.Crashed/bashed/recently redone.

His sprockets ONLY HAVE NUBS!!!!!
I have a used set.I only run up to about 12000 miles on ANY set of sprockets and replace the CHAIN along with them.Enough about me.

HE has an old 520 chain currently and wants my old sprockets from my 2000 996.

Are sprockets dedicated to EITHER 525 OR 520? Do the chains interchange?

 

[916duc]

Your 2000 996 runs a 525 series/size chain and sprocket, his 520 chain will not fit it. The 520 link will be too narrow / small to properly fit the tooth of the 525 sprocket and the pitch / spacing is also different.

If he tries to force the fit, he will most likely break the chain and or the teeth on the sprocket. A broken slapping chain can easily punch a hole in an aluminum motor case......... YMMV