Thought I only posted under expert area sorry

 

I have noticed on a few occasions that I will get some sort of sputtering that sounds a lot like some of the symptoms described earlier in this thread. I can't recall a full stall condition but I always back off when it begins to sputter. I do notice that it seems to happen only when under heavy load. First few times was when I was plowing heavy snow and the latest was yesterday when pulling a dirt harrow that was heavily loaded down. The times in snow, I eased off, let it cool a bit and then was able to resume work. I chalked it up to reduced air flow due to the plow.

Yesterday, in the dirt work, I unhooked, put it in high range and went for a light 20 mph cruise, hoping to cool it down. Once I returned to working (about 86 deg. ambient) and started pulling again, it wasn't long before it was doing the same thing.

I decided I would quit until another time, but by the time I got turned back around where I could unhook the harrow, it stopped sputtering and acted like nothing was wrong. I made a few more rounds and had no troubles. I unhooked after finishing up, went for another cool down light cruise and I notice that if I back off the throttle quickly, it will backfire once, but not every time. If I give it full throttle, it almost acts like a plug partially fouled.

I have the updated ignition system that OPT mentions. I put this on several years back. Any further suggestions on things to check?

 

Make sure you don't have too much slack at the thumb throttle.1/8" max or it can backfire or die if the etc contacts bounce and touch. Make sure the radiator isn't blocked,especially around back around the fan area,coolant level is full and that the fan cycles on and off ok.An intermittent problem may be hard to trace but you can eliminate the easiest and obvious things like the radiator,fan,etc switch and possibly even draining the carb to see if has any water or trash.It may be due to reduced air flow when working,but may not be enough to trigger the hot light. If you have to, pull the fan or even the radiator to make sure you don't have any caked mud and wash it out thoroughly. Plus check under the clamp on the intake manifold. Known problem for a lot of them to split at this area causing them to run lean.Hard to see if it is with out removing the clamp.

 

Thanks, OPT!

 

Hope it's something simple as we usually didn't have any complaints with the Kokusan ignition updates.Plus some other things to check that others have posted about are tank venting. Make sure the vent is open,plus another is the fuel tank insulation. You can even try to operate a few minutes with the cap off and see if it helps. Under heavy working conditions the fuel tank and fuel may get hot also and cause a vapor locking type problem. Some have added extra heat foil around the bottom and sides of the tank.Hopefully between making sure the radiator is clean and possibly adding extra insulation you can solve this.Keep us updated as to what you find out.

 

Can the gap be adjusted, or do I need to order new parts? It's certainly no less than 1/8" when it opens up as I touch the throttle lever.

 

Only thing you're doing is taking up an excess slack from the cable. More than 1/8" and etc contacts in the housing can briefly touch and this can cause back firing also as it retards spark. Too much and it will die at an idle. http://www.ehow.com/video_4468404_polaris-atv-thumb-throttle-maintenance.html

 

Thanks again.

 

As it turns out, it was a bad plug wire. I'd have not suspected that at all, since it was so intermittent. Ended up taking to a dealership because this fall has been hectic and I just plain didn't have the time to troubleshoot anymore. I'm glad I did since they found a cracked exhaust manifold and bad donut gasket. I didn't even notice that and I'm usually pretty **** about such things.

 

Both can cause one to run crappy. Glad you found the problem or rather the dealer did..