My 03 Trail Boss has no more than 250 miles on it. When I start it cold it has a knocking sound for a couple minutes and then the noise fades away. It's an obvious knock sound and it happens inconsistently about every second or third start. It's definitely from the engine (not the starter) and may be coming from the lower end although the sound is similar to a stuck lifter on a car engine but a little more hollow. I'll take it back for them to look at as it's under warranty. Any suggestions? While I'm asking questions here is another...It died two hours into riding two days in a row. I tried to restart and no luck. I then put it on reserve fuel and it started right up and then switched it back to full on fuel position and it kept on running the rest of the day. It had plenty of fuel and I never did hit actual reserve. What could that be? Thank you again for the help.

 

That doesn't sound good to me, sounds like something mechanical going wrong. It almost sounds like you are running lean and it is overheating. The time you messed with it to turn the reserve on, may have been long enough to let it cool enough to re-start?? Is your oil pump working correctly?? A lean engine will run better as it warms. You may also have a bad gas filter or some kind of restriction in the line or tank starving it for fuel??? You could also have an airleak somewhere?? Just guesses, I would take it back ASAP while it is under warranty and soon so they can't try to blame it on abuse or anything. Just my .02

 

It's not hot as it only happens from a cold start and I know it's not hot. As for the the gas problem, I turnned it to reserve immediately just moments after the stalling. Thank you for your thoughts.

 

It sounds odd, I would take it back to the dealer and get it fixed. There could be something in the petcock or gas tank that is causing the gas to quit flowing, if only for a few seconds and once you turn it to reserve it flushes it back out into the gas tank?? Only thing I could think of. That knocking could be detonation, piston rattle, bendix sticking, or the clutches?? Who knows, it is hard to tell anything without actually hearing it, take it back to the dealer.

 

I went to the dealer tonight and told the mechanic about the engine noise. The quad was cold and we started it and it made the noise I described above. He listened and said it was normal. So we went to an 03 Trail boss like my own to start that he had in the shop - we started it cold and no noise like mine. He still insisted it was normal. I just want to be sure nothing is starving for oil at start up and he said although he wouldn't work on it for the complaint, he would place a copy of the work order he had written on the complaint on file for future reference. As far as the stalling that seems to be related to a fuel flow problem, he said it may be something in the tank but he doubted it and wouldn't look at it either for a fix. He said I should continue to ride it and if anything should develop into a larger problem I can bring it back for service. I am not too pleased with the answer I received. It is three weeks old. Thank you all for your thoughts on this matter.

 

is it low on oil?

 

Please, no it is not low on oil.

 

It could be piston slap, when the piston has to warm up to fit to cylinder properly

 

I kind of agree that it may be piton slap or rattle, I believe I mentioned that earlier. I think that is pretty bad and I wouldn't be happy with that answer either. If it is stalling out and dying, then that is a problem, not a complaint and they should check it out to see why. I would talk to the manager about this and If they won't do anything, call Polaris and complain. Just my .02

 

I know in the car business they call this a "nuisance" not a problem and I have heard some very loud ones and the factory wont fix them

I wouldnt be happy if after spending the money on a car or quad that had this condition I would be looking to the mfgr for some help