my 2002 sp 500 h.o will not hold a steady idle, it varies from too low, then give it a little gas, then it idles so high you cant put it in gear. i drained the gas so thats not a problem, the filter is a k&n and is cleaned and oiled as well. the bike was backfireing like crazy as well when you would get up to 30, and let off the gas. the bike ran great before this, so it doesnt make sence to me? now the other thing when it was doing this eratic idle, like an air lear or something, it shut off, and some grey smoke came out from the top of the engine head. the motor doesnt blow smoke or anything like that, it prolly only has 2000mi on it, any help would be great

v581

 

maybe your head gasket is gone and its sucking in to much air?

 

A few things to check. Make sure there is not a crack or air leak on the carb boot. Also, when is the last time thta you had your valves adjusted?

 

ok let me say thanks for the quick replies, first it sucks to say i dont feel well so i prolly wont look at it for a day or 2 [img]i/expressions/face-icon-small-sad.gif[/img]

i know the intake boot is not ripped i had checked that, i remembered i had that problem on a explorer 300.

now i was thinking the head gasket to, because the motor head is really oily looking/ dirty, as oppose to my vinson where the motor shines, and has more milage. now a buddie of mine has a duse 500 ho, and his bike runs fine, but has the same oily appearance. i will take a look at the gasket, and as far as the valves being adjusted, hmm.... never, at least it is safe to say it isnt my bike [img]i/expressions/face-icon-small-smile.gif[/img] i wouldnt treat it like that, now can i do the valves myself, i did my 230's valves myself, but they are much simpler, and my vinsons i had the dealer do, because they had it there anyways. thanks guys

v581

 

My motor has no oil or dirt on it. I clean it really good after every ride though. Could be a head gasket, but I would think you would see some white smoke coming out of the exhaust. The valves are recommended to be adjusted every 100 hours or 500 miles. You are probably overdue for it. They are fairly easy to do. Just a matter of getting the front plastic and gas tank off to get to them, then finding TDC on the compression stroke. All you do is is pull the timing chain cover off to verify TDC, pull the valve cover off, and adjust th valves to .006" clearence. You will need 2 feeler gauges to do the exhaust valve though because it shares a common rocker arm. I have the procedure to do this for the 500 HO motor scaned from my manual. If you do decide ot undertake it, let me know. I can send you the pages from my manual

 

thank you , i do have a polaris repair manual.

v581

 

One more thing to check that will cause the problems you describe...check and clean the ETC switch and make sure your throttle cable is adjusted properly. Simple item that is sometmes easily overlooked. Goodluck!

 

what is the "etc"switch, and where is it located?

 

The switch is supposed to kill the engine if the throtle gets stuck open from a froze cable. The switch is right inside the thumb throttle...just pop the cover off the top and you'll see the switch. If the throttle cable isn't adjusted properly (usually a hair too tight) or the swich contacts are dirty of defective it will cause it to act up...