[turnerdesign]

I have an 07 Sportman 90 that has run perfectly since the day I bought it new. The kids grew up and I sold it, to my nephew. I rolled it out of the truck, started it, and his boy rode it off. After about 100' it had problems. It idles fine, but any throttle just bogs it down and it chugs along, barely. I cleaned the carb, replaced the jets and no change. I took it to the dealer and they had no answers. I bought a new CDI box, but the one that came was for a CRF 50F. But it has the same part number, wierd. Anyway, I put it on and it does roughly the same thing. But any throttle at all and it dies instantly. Putting on the old CDI produces the same results, giving it throttle bogs it down, but doesn't kill the motor. Could it be anything else? Any way to test it?

 

[Matty]

Flat spotted rollers in the front clutch in the transmission. Replace just the rollers with stock or change them with different weight rollers along with the springs in the rear and you can wake the machine up

I went through the same thing with my kid's 2003 Arctic cat 90, it's common across the whole spectrum with the little machines. I ordered a set from west coast quads, I installed the performance setup vs the stock. It really woke it up significantly.