My neighbor asked me to help him with his Sportsman 500. It will start and run for about 7 seconds, then die. Sometimes spits and pops when it dies. I can restart it again but dies after about 7 seconds. The sparkplug looks like a very rich mixture. I noticed right before it dies a drip of fuel would come out of the over flow on the float bowl. He had a Chinese carb on it, but ordered a 34 mm Mikuni off of eBay and I cleaned it up and installed a Moose carb kit. Same problem now but no drip of gas before the engine dies. Fuel and fuel flow are good from the new fuel pump. The sparkplug is good and gapped to .025. The throttle cable is properly adjusted and ETC is working correctly.
Any help would be greatly appreciated.
Thanks, JC

 

Will it stay running under throttle? I would guess its either the float out of adjustment or the mix screw set to rich.

 

Thanks, for the reply.He had someone else working on it before me and the guy replaced the CDI. I ended up putting the original CDI back in it and the thing ran and idled great up until you hit about 15 mph, then rev limiter would kick in. I found that the shifter switch was bad. My neighbor was on a budget of about $0.00. So I had to get creative.That darn switch is $125!!! So I wired around that, I also disconnected the black wire from the CDI and rerouted wiring from the rev limiter, so the AWD will function when you push the button. He now has to make sure that he's in neutral upon start up, because none of his idiot lights work (reverse, neutral), after disconnecting the shifter switch and it WILL start in gear. Polaris has a rev limiter in this thing so you can't run it really hard in FWD, because the front differential can't handle it. So he has to make sure he doesn't run it in four wheel drive very hard (4000 RPM's) because the rev limiter is no longer hooked up. I got it up to about 50 mph indicated.