Just picked up a 2002 650 Prairie and the PO messed with the carbs and now it will spit and spudder once the choke is turned off. Unit has a K&N air filter and a aftermarket pipe (pro circuit T-4 ) and he said he did a rejet but I think he might of changed the pilots. Might someone know where I would start with jetting to atleast get it running better so I can then tweek it. Also should I shim the needles. Im going to order the stock pilots so atleast I know they are right. Thanks for all your help. My nine year old son also thanks you.