Todd, This may be a long shot but I have seen this on several 500's . Check the rubber conection between the Carb and the cylinder. Make certain that there is a good leak free conection between the rubber tube and the Carb and cylinder. I have seen this be the cause of several 500's not wanting to idle properly or run right. If I'm not mistaken this same problem also led to Bill Cilibertis Sportsman 500 Engine failure. Another area to check is the Carbs vent tubes be sure they are open. Also check the Enrichment system(Choke) make certain it is not partialy on. This will cause a rich condition esspecially after the machine warms up. You might just back it off completely if you don't need it to start the machine. Simple things first!!

 

Hey guys i have the exact same problem with my 94' timberwolf it's a bi*ch to start cold and once it does start it will idle but a touch of the gas and it dies. also at idle whether hot or cold it runs at different speeds varying about every 5 seconds but at random not consistently. Could this be the same kind of problem.When i took it in for a check up about 6 months ago i asked and they couldn't figure it out.

 

This is a long shot but my sons yamaha had the same problem woulnt start when it was cold. Once you got it to run and it heated up it ran fine. Threw me for a loop then did a compression check and there was none when it was cold. When it was hot it had compression. Turns out that the valves were to tight, and when it got hot motor expanded enough to let them seat.Seams that the valve seats wear down and you loose the valve lash completely supposed to be common problem on Yamahas. Just a long shot.

 

Here's the LATEST !!!
I think we've found the problem!! A bad rev limiter!! The stator came in and Rodney (my mechanic) changed it out....no difference....unhooked the rev limiter and it runs fine (although when I talked to him yesterday afernoon, he didn't know if this would affect the four-wheel drive...I know it does in reverse??) He's gonna order a rev lmtr for me. Anyone know how much and how hard to install this thing is? I haven't looked in my manual yet to try and locate it, but when I get it home today I'm sure I'll have to "tinker" with it.:-D

I'll report further as news develops...(I outta be on TV)

 

If the new rev limiter doesnt make a difference, then check the timing. The rev limiter controls the timing and when unplugged the motor timing may change enough to run ok. Just an idea. I may be wrong.

 

Thanks, Joel, I'll check my timing. I haven't done that thru this whole ordeal. I read how to do it in my service manual, but do I need a special timing lite, or will a regular automotive one work?

 

It sounds like you are sinking a lot of money into this problem. That stator assembly alone is about $250. I dont recall ever finding a bad stator but the pulse coil, I have replaced many of those. This is attached to the assembly and most early parts manuels dont show it seperate and that it can be ordered for only $50. There are resistance checks to test the stator components.

 

It sounds like you are sinking a lot of money into this problem. That stator assembly alone is about $250. I dont recall ever finding a bad stator but the pulse coil, I have replaced many of those. This is attached to the assembly and most early parts manuels dont show it seperate and that it can be ordered for only $50. There are resistance checks to test the stator components. I have seen reverse speed limeters act weird when cold also. Disconnect the black wire to this and see if the problem goes away.

 

Never done it to a Sportsman, but on pre electric speedo you can just unhook the black wire on the limiter and it will disable it. That should tell you if it is bad. Will run fine with out it just disables some of the safety features.

 

Hey Richy!!
You just solved my sled "problem". When I first start it, I have to keep it running with the primer. If I touch the throttle during the first 20 seconds, it will bog.
I'll put a fatter pilot then.