I have a 98 polaris 400l sport and all of the just last week it started backfiring. i was wondering what might cause this. i looked at the plug it was not fouled. the gas was good i do not know what the problem could be any answers or suggestions would be greatly appreciated. i also have one other question the revers quit working also what could cause this. it sounds like it wants to go but just does not go

 

A 2 stroke will often backfire when running too lean. Maybe the cold weather is causing a lean mixture.

 

Is your quad piped? When I got my pipe installed it would just spit and sputter in reverse...without moving. Need to use the overide all the time now. Is this your prob?

 

make sure the contacts are closed in your throttle control. had the same prob with my 98 sport!! if they are too loose, you can hear em click when the thumb lever is bearly moved!!! alot of people dont think about this but when those contacts open, it tries to shut the motor off which causes back fire!!!!!!! that is polaris way to shut motor off if the cable should break.

 

i do have my quad piped and i also have a clutch kit. i do have to use the override button like you said. but i tried it and it still did not work maybe because the machine was not warmed up all the way. but im not sure. but thanks for the info i will still try and figure it out. thanks for the help though