How to mount a 12T 428 sprocket on a CG engine?

[Mudflap]

I've got a 13T on there now which required some grinding on the retainer and use of socket head screws instead of hex bolts, but would like to use a 12T. The problem with the 12T is there is not enough space for a stock type retainer as the chain plates would contact even socket head screws. The only solution that comes to mind is using a spacer behind the sprocket to hold it in the correct position, and a snap ring to hold it all in place.

Anyone have a better idea?

[Weldangrind]

Maybe a 520 conversion is the only way.

[Mudflap]

How many teeth do the newer 520 chain models have on the rear sprocket?

I got it to work by making my own keeper and grinding the socket screw heads to a smaller diameter. Gear ratio now is 3.33/1 which is better for my uses. I had been riding it for over a year with a 3.07/1 ratio but 4th gear rarely got used. The original ratio is 2.67/1 which is WAY to tall.

[Weldangrind]

I have no idea about the tooth count on newer China quads, 428 or 520; it was just a random thought.


Is there any opportunity to change the rear sprocket to a larger size? Got pics of your mods?