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Discussion Starter #1
I am the 2nd owner of a 1995 Polaris 300 4x4 that's in great shape, only 1500 miles. Problem is it just will not idle. Its either so high that I cant put it in gear without grinding or so low that I have to stay on the throttle to keep it running. I rebuilt the carb and no change. Jets are factory spec and runs best with air screw out 1 1/2 turns. I am suspicious of the 3 small vacuum lines and the correct routing. Can anyone tell me or send a picture of how they route? I am going to order a new rubber intake boot too, to see if that helps. Any advice please? I know 2 strokes can be finicky but hey, my stupid weed whacker is a 2 stroke and that will idle all day.
 

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Have you tried making the adjustment at the upper end where the cable attaches to the throttle?
 

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Discussion Starter #3
No, I have done all my idle speed adjustments using the stop screw on the carb itself.
Is there any chance the ETC can be the problem?
 

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I got mine as close as I could at the carb then used the upper adjustment screw to fine tune. ETC is possible but not probable. That's easy to check. Just pop the top and see if it's moving along with the throttle as it should.
 

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Do a air leak test to find out if you have a air leak around carb when it is idling take a can of starting fluid and spray around the carburetor and the intake boot and around base gasket on cly. then if can spray in recoil rope hole and if you have clutch cover off spray behind primary clutch to check for crankcase seals leaking and sucking air,
when spraying if the idle changes at all up or down check twice that means you have a air leak which makes a lean condition
 

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Discussion Starter #7
Thanks. I'll try the starter fluid check today. I hope that it is just something as simple as the carb intake boot. I cant imagine that with such low miles that the crank seals could be bad. With a coat of wax, this machine would look like new. Prior owner only used it a few times a year for ice fishing.
 

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Discussion Starter #8
Well now I feel pretty stupid............The suggestion of an air leak causing the idle adjustment problem got me thinking. In the spring I had a problem with the starter being intermittent and then after a few weeks, just not working at all. I bought a kit to rebuild it. Upon disassemble I discovered the starter was full of gas. (There had been a few instances with gas leaking out the carb overflow if I forgot to turn the petcock off) So during reassembly I note that there is a small drain screw directly below where the starter housing is. In my infinite wisdom, taking into consideration the pita job it was getting the starter out, I decide to leave this stupid screw out so if I do get a flooded engine situation, the starter will not fill to the top with gas again. Last night I put a new screw w/brass washer back in this drain hole and it now is much better. Not perfect but much better. Following this, I sprayed starter fluid near the carb intake boot and no rpm change. I then sprayed it in the pull start rope hole as suggested in this forum and it caused the engine to die. So now my question is, does this mean I have worn seals in the bottom end that need replacing? The pull start handle has a tight sealing fit when properly seated. I could probably live with it............I assume seal replacement entails completer removal and disassemble of the engine?
Great Forum!
Thanks for the help
 

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You have a bad crank seal on the recoil side. Time to replace it before you do major engine damage with it running that lean. Do the other side too while you're at it and save the headache of doing all the work a second time.
 
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