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?