I have been helping a friend with a 2003 Polaris Predator 500. This quad wouldnt run and had no key. we took out the tumblers in ignition so no key is needed. First he could get it to fire once and then no more He waited a bit and tried again. We have fuel ,not the problem. After a couple days I accidently forgot to let go of the starter button and it stayed running until i let go. We changed the starter ,off on switch not the problem. we also bypassed the ignition and the throttle stick override ,still the same. Any ideas we also cleaned up all the grounds on frame we could find. also battery is junk so we have it on a charger.

 

I forgot we eliminated stator problem it does the same thing.

 

So you have fuel and spark? How bout the timing? My buddy's timing chain stretched and he couldnt get his to run. He also had to buy a new tensioner. I would look into that. I sold my 03 last year, but it was definately a warm blooded monster. I always had trouble getting it running in the winter. And you need a good battery for sure. So I would replace it also. You'll need a new one anyway. You don't wanna stall out in the woods with no one around cause you'll be screwed trying to push start it.

 

Sounds like a timing chain problem. Take a compression check. Do you have any prior history as to the last time it ran good? What happened since then?

 

what about the valves, have they been adjusted?

 

Sorry I did not say it won't start. It does start and run as long as you dont let go of the starter button. You can rev it up and shift. But once you let go the button it quits and you have to turn off and back on to start again.It is electricle but where? Thanks for replying it is much appreciated

 

Is the starter staying engaged when you do this?

 

yes it is turning but not engaged with the engine,just spinning.

 

yes it does continue to spin but not engaged.

 

You said you messed with the key switch, I would look there first. Sounds like when you return the key to the run position you are cutting off the juice to the coil. look for an open in that wire