1999 Polaris Sportsman 500 Motor Knock

[grun]

I have a 1999 Polaris Sportsman 500 ,Last summer I went on an ATV run of about a hundred miles, Towards the end of the ride I noticed the motor was starting to knock and it did not seem to have much power,especially upon acceleration. When I got the machine home I had the cam replaced which cured the knocking but when I test drove it at the shop the power still was not right...actually not any better than before the repair. I told the mechanic about it and he messed around with it for a few minutes and determined that the air box was not sealed properly and put a new gasket in. The problem seemed to be solved but since I got it home the problem has resurfaced. I tested the compression ,It's fine and,replaced the plug and fuel filter to no avail..The problem is not constant ,sometimes it runs great. What do you think is the problem ?????.OK tomorrow I will probably take the carb off and clean it but, I will try to explain exactly what happens ...It starts and idles fine but when I push the throttle, wheterh it is in gear or in neutral the engine does not snap up the RPMs quickly ,it seems doggy and will not rev to the limit like it used to ,..When riding it has no power from a dead stop and will reach 30 mph or so slowly it will eventually get up to about 45 mph but it takes a long distance to do this , when it was running good I could get to 55 mph in about 10 seconds,.. now it takes all day to just get to 45 mph..I just want to be sure You guys have all the info you need before suggesting I tear the carb apart.

Edited February 7, 2009 by admin
No title

[Sparrows]

post name?

[grun]

What ??

[BuckBilly]

Hey Super Duper Mods !Can we get a name for this thread and move it to the Tech section of the forum ? Please!!!!!!!!!!!!

[Admin]

Thread moved and title added.

[BuckBilly]

Thread moved and title added.

Thank you!!!!!!!!!!!!:bow::bow2::hurrayc:

[Sparrows]

hahahaa thanks!

[ATVmechanic]

What's the status on this thread? Still having issues?

[grun]

I just put the carb back together after a good teardown cleaning and it runs like a new machine!!!

[ATVmechanic]

I just put the carb back together after a good teardown cleaning and it runs like a new machine!!!

That's good to hear!!!