Inconsistent Idle / Chain Ajustmeant
 

Hi, I have a 95 Polaris xplorer 400 I had 2 quick questions on.
Idling problem: I've found (and dealt with nearly a year now) the idle on the atv seems to decide on it's own where it want's to be. After cleaning the carb for this season I ended up turning the idle down at the throttle block close to 1/8 (Possibly a touch more) before it would idle right. Then after playing with it a little It seemed I would chase the idle to low or to high for a while until I got it where I wanted it and then five minutes later be increasing or decreasing it to make the atv happy. This may be due to over oiling as I replaced the oil line recently after it started leaking from a crack and premixed my gas doing so likely causing the plug to want to foul easily causing my sporadic idle?. I wanted to see if anyone had any thoughts on this? (Intake boot and carb/air box boot look okay)


Rear Chain tension setting: Also for about the past year I have been having trouble with my rear chain being to tight (or loose) causing my chain and gears to pop in reverse and strenuous hard take off in forward. I wanted to see how loose I should be running the rear chain when adjusting the rear housing? If I'm correct it is supposed to have been 1/4 inch loose but wasn't 100% sure and wanted to ask.
Thanks!

During this time have you done a leak down or replaced crank seals? May be the problem on the erratic idle if you haven't.
I always kept about 3/8" slack in the middle on non concentric and also concentric drive models that came out somewhere around 97/98 or so.More forgiving on the concentric models as the swing arm pivot was in line with the sprocket and had less effect on the chain.If the chain keeps loosening and tightening,sounds like it could be the chain itself if it's been on awhile. Check the side to side play on chain links. If there is any replace the chain. Same for any stiff links,chain needs to be replaced.

Thanks! I'll have to see about doing a leak down test soon as I have never done so on the motor. If I'm correct I need to block off the exhaust, intake and possibly the oil line before pressurizing the engine from 7 -10 psi with a pressure gauge installed in one of the block offs. Anything more than 1-3 psi loss within ten minutes should indicate a leak beyond what may be a leak in my block off's? I will adjust the chain if possible tomorrow to 3/8's like you said (Chain is almost new - less than 150 miles, will check for any play / problems regardless) Thanks Old Polaris Tech!

Several different leak down tests on youtube to check for seal and case leaks.