Hi everyone - first-time poster.

I've picked up a 2000 Sportsman 500 HO off someone for a song a while ago and have been trying to get it back on the road.

Some of the electrical has been jumbled in order to bypass the key ignition (I'm assuming there's a bad contact in there), so it's basially been wired to start without the key. That isn't my issue, though.

Basically, I have power to the starter, fuel, spark and air. I haven't pulled the stator to check it,. since I'm getting strong spark (assuming the stator is fine). The ETC has been set properly and everything else that any other conventional engine needs to run is there. And yet, it won't start.

The starter is turning the bendix and the engine is turning over no problem. Fuel is going though the carb (which is fairly clean) and all of the wiring matches up with the necessary resistances that my wiring diagram is telling me.

The only sign of life I'm getting is that the air box gives a periodic "huff" (almost like a backfire)

I've even tried disconnecting the kill system (blk wire from the CDI thinking that it was the issue. I can't seem to find any obvious grounds that could be preventing a start.

Any thoughts? CDI box, maybe? I want to get an idea as to what else I need to check before resorting to buying a puller and checking the stator directly. All of the connections to and from the stator are solid.

Any advice is greatly appreciated.

Thanks!
Cameron

 

First thing that comes to mind is to pull the cam cover and check the valve clearance (.006 intake and exhaust) plus check the exhaust lobe on the cam. Common problem on the early models on soft cam lobes.If it's ground down,plenty of after market cams and the exhaust rocker arms on ebay for the 500 now.Plus here's one members pics on his Scrambler 500 cam. Bad Cam Pic - ATVConnection.com ATV Enthusiast Community