anyone have a clue what the factory primary clutch spring rate may be?
I think they use the stock prairie 650 spring. it's a solid plain spring with no color or stripe. they are a zero stall and about a 135-140 shiftout. very wimpy spring.
try a spring like the Dalton Blue or EPI pink in it. 0-158 ish You don't want to get too stiff of a spring as they are only 400cc and will not like revving that high.
the stock springs are weak and collapse after time. they are a different clutch with the square faceplate and the wide spider.
How would that spring work in a 550 mule??The Vforce spring isn't that much stiffer. if at all. they are similar. it looks like a 2002 p-650 stock spring. The weights in the mule are thick and lumpy. that keeps the RPM's down as they are only geared for 30 mph if that. I think they shiftout in the 3000 range stock.
Now a stock Teryx spring would probably be the ticket they are about 150 shiftout range. I have probably 50 of them here. if you want one you can have it for the cost of shipping.
You can do the throttle governor mod by drilling a hole in it by the backside where the spring goes to let it overrev. that way, you can ruin the motor as the throttle is governed by the metering rod. you can get prob 35 -36 mph out of it that way.