[Arsenal]

Hey guys,

Slight problem on my 04 500, It seems like it wont idle at all unless the engine is warm. And its very hard to start. Normally always have to use the pull start to spin the engine fast enough to get it running. (could be another problem with my starter)

Any who, it does it at all temperatures below 65 degrees and the colder it is the worse it gets. I have taken the Carb apart multiple times. cleaning every time. I have bought a carb rebuild kit and swapped out all the jets, adjustment screws and needles that the stupid thing has. Float valve and seat are brand new. Jet needle is brand new and the clip is in the proper position.

I had a Polaris tech mention something to me about maybe the idle jet is supposed to have emulsion holes in it? or its not supposed to he couldn't remember. and dummy me lost the old one before I had a chance to check.

I had the carb apart last night and I went to town on it cleaning everything with 90psi compressor and carb cleaner. I thought it may have been the choke circuit but i can stick the little red carb cleaner tube into the hole where the plunger sits and shoot it in and it jettisons out the pickup in the bowl just as fast as I'm spraying it in and the same with the idle circuit...

I can crank the idle speed up when its cold which works great until it warms up and the the idle goes to like 3k RPM's and you cant shift or do anything.... oh and my idle/air screw is adjusted to 2.75 turns out as per the manual.

PS. I adjusted the throttle cable and the choke cables to spec, with no change. I wonder if its possible the ECT is bad? but wouldn't that cause crappy idle even when warm?

 

[Russ C]

Some of those machines were jetted too lean from the factory, try going up one size on the main jet.

 

[Arsenal]

I'll see if I can get my hands on the next size up idle jet and see if that helps. Thanks, I'll let you know.

 

[fhedrickjr]

I'll see if I can get my hands on the next size up idle jet and see if that helps. Thanks, I'll let you know.

When is the last time you checked the valve lash? I had a very similar problem on my 04 400 Sportsman. Finally, my Cousin took it to a local shop we deal with near Princeton. After fiddling with it for a bit, he checked the compression, which was down to about 28 lbs. He checked the lash on the valves and there was none. He lashed them to the proper settings and it starts right up and runs like a dream now. Prior to the no start condition (which was in colder weather), it would start but would not idle correctly. I would turn the throttle adjustment up so it would idle, then, when it was warmed up, it was idling too fast. Would adjust it back down, then, on a cold start up, it did it all over again. Sound familiar??

 

[Arsenal]

Hahaa! That sounds exactly like my problem. And if there is low compression that might be why when I try to start with my electric start it sounds like it's spinning the engine but I can't hear the compression stroke.... By golly you might be a genius. I'll have to borrow a compression tester and some feeler gauges from my dad and check it out.

 

[Arsenal]

I was just checking out my service manual and it looks like these engines have adjustable valve clearances? And don't use a shim. That should make maintenance easy

 

[Russ C]

Set both intake and exhaust at .006, I wasn't talking about the idle jet, called the pilot jet, should have a # 40 in it, I was talking about the main jet, depends on elevation as to whick one it has, you can read it on the jet, Im guessing it has a 140 in it, go to 142.5, Is it hard to start when cold? Also check air fuel screw on bottom of carb, should be set at 2.5 turns out.

 

[Arsenal]

I put a dyno jet kit in it.. I believe the dyno jet kits have different numbers. But I followed the elevation and temperature guidelines when picking my jet.
And those kits don't suggest you change the pilot jet so I just left it stock. If my understanding of a carburetor is correct the main jet wouldn't affect idle speeds. The main jet comes into effect at throttle ranges of 1/4 open and up. I went through the whole carb and adjusted everything so I put my screw at 2.75 turns out which is what the service manual says.

 

[fhedrickjr]

Hahaa! That sounds exactly like my problem. And if there is low compression that might be why when I try to start with my electric start it sounds like it's spinning the engine but I can't hear the compression stroke.... By golly you might be a genius. I'll have to borrow a compression tester and some feeler gauges from my dad and check it out.

Hardly a genius. Spent the better part of 2 or 3 days, several trips into Princeton from Camp Creek, new plug, new battery, lots of time spent being confused and aggravated instead of riding. I had never heard of valves tightening themselves. My guess would be that the seats had worn just enough to take up the lash, then, wear just enough further to cause the loss of compression. All in all, lessons learned. Still a very sweet little machine.
Hope this works for you!

 

[Arsenal]

I'll be checking my compression tonight. Book says it's supposed to be 50 to 90 psi so that should tell be pretty quick. Is pretty cool they give you adjustable rocker arms instead of having to replace a shim. I'll keep you posted on my findings

 

[Arsenal]

This made me very happy!!!!! The exhaust valves were very tight. I checked the compression and was about 25psi so I pulled the gas tank for better clearance. Broke the plastic fitting off the fuel shut off. (Bypassed anyways). And as I unscrewed the rocker arm adjustment I could see the sitting decompress and said to myself BINGO. Set the proper clearance and put the valve cover back on then went to pull start it and had so much of a compression stroke I broke my pull start handle right off! Do I tied that back on and gave a yank. Started first pull! She was in a heated garage but engine was cold and she idled perfect! I left her out side for the night and I'll see how she starts in the cold NH winter morning! Thanks all!!

 

[Russ C]

THe Valves get tighter cause they wear into head where they seat, sounds like you found it.

 

[Arsenal]

Now I just have to fix my starter. It's still messed up. I think my Bendix is just bound up though. Should be an easy fix. Just gotta do it....

 

[fhedrickjr]

Now I just have to fix my starter. It's still messed up. I think my Bendix is just bound up though. Should be an easy fix. Just gotta do it....

Very cool!! Yeah, another common problem. If you go into deep water without the pull handle being firmly seated on the case, you get water and muck in there which causes things to not work properly. A thorough inspection should hopefully show some mud and or corrosion which is an easy fix. If you can't salvage the parts, they are not hard to find. Glad that worked for you!!

 

[Arsenal]

Yeah. That was a the easy solution. I need a new Bendix. Looks like the little spring that goes around the 3 cam type things on it broke. I couldn't find a spring that small at my local not so helpful place. So I'm just going to have to get a new one. I'll probably end up sucking it up and buying the two bushings on either side of it as well so u can finally do away with the horrible rattle it has. I don't even think I have the right pull handle because even firmly seated it leaks water... Seems like the seal is too big for the mount on the case where the rope goes in. So I did the natural thing (temporarily), I duct taped so it fits tight.

 

[fhedrickjr]

Yeah. That was a the easy solution. I need a new Bendix. Looks like the little spring that goes around the 3 cam type things on it broke. I couldn't find a spring that small at my local not so helpful place. So I'm just going to have to get a new one. I'll probably end up sucking it up and buying the two bushings on either side of it as well so u can finally do away with the horrible rattle it has. I don't even think I have the right pull handle because even firmly seated it leaks water... Seems like the seal is too big for the mount on the case where the rope goes in. So I did the natural thing (temporarily), I duct taped so it fits tight.

Hahahah!!! My Cousin was so mad at his son for dunking his, he threatened to use black rtv to seal the thing!!! I had thought of using a tie-wrap to snug it up a bit...

 

[Arsenal]

If I didn't rely on the pull start I would have cut the rope and capped it a while ago..