520 Sprocket Conversion


Sprocket Catalog w/dimensions


falconman wrote:


To convert a triple to a 520 chain set is easy. Just get the correct sprockets and chain. For the front use Sprocket Specialist p/n 513-X or p/n 524-X (X=number of teeth). These will work on any triple (250-750). You will need to make a .1” (0.100) spacer to fit behind the sprocket. If you are unable to obtain a spacer, Sprocket Specialist p/n 504K-X has the correct spacer but the sprocket itself will not fit any triple.

Note: The front sprocket spacer can be purchased for like $8 Kawasaki part #92022-288. The outside dia. is a little big but clears just fine.


For the rear you can have Sprocket Specialist make a custom sprocket (expensive) or use one from another model that will fit that is already a 520 size. Following is a list of interchanges that I have found thus far.


S series rear –


For the S series I have found a sprocket app that is close. It would only need the bolt holes slotted 1mm towards the outside of the sprocket. A 3/8ths file, mill or drill press with cross slide could be used to slot the holes. The sprocket centers on the center hole so slotting won’t affect mounting. The slotting is also minimal so it will not be seen once the sprocket is mounted. The p/n is JTR1414 or S.S. 297. The original app is a KSF 250 Mojave ’87 – ’02.



H series rear –


500 – use S.S. p/n 278-X or JTR Sprockets p/n 1458.  This sprocket is from a ‘78-’79 KL250 A1/A2/A1A.


750 – none found yet.


If anyone finds a better fitting sprocket for the S series, one for an early H1 or for an H2 let me know so I can update this document. Thanks!







PBI Sprockets offers Triple 520 rear sprockets. Check their catalog: http://pbisprockets.com/

Base sprocket numbers are offered in various widths and tooth count.






Yamaha Parts Conversion



Spacers machined from 4340 or 8640 steel

Sprocket is from RZ 350 or RD 350LC

Medium strength loctite advised for assembly.