Rear sprocket size
 

What are some recommendations for a 520 rear sprocket? Specifically model numbers. I ordered a couple but they were the wrong size of mounting holes (the descriptions didn't include that). So far I can't find what size mounting holes I need and most of the sprockets don't list what they are anyway.

Size mounting holes? You just go online and select 600F4i and buy the sprocket. I've gone threw at least 6 rear sprockets from Renthal, AFAM and Superlite and never had a problem. Where are you ordering from?

I'm doing the 520 conversion and was trting to order off amazon since i have gift cards there.

Ahhh gotcha. Go online to motosport.com or something similar to search the correct part number for the brand you want. 520 is the only way to go :)

Can someone shed some light on what a stock 04 f4i has in the rear and what would be the better upgrade (if any)? I take it the more teeth in the rear the more acceleration and lower top end and less teeth is vice versa.