Im just wondering if I am the only one with this problem on my atv I had it fixed when it was knockin 2 years ago and that time it was the cam and rockers.But im not sure if its the same noise I have heard before and I also want to know if im the only person who had had that problem.I tried puting some ticker oil and oil aditive and its still knocking.Also I would like to know how to maybe stop it so that I can trade it in on a Can Am 800.

 

Are you absolutely sure its the motor knocking? I had a knocking sound once on my old Prairie 650 and I thought it was the motor...however, I noticed it only knocked at idle and once I revved up the motor, the knocking sound went away. I later discovered it was my primary clutch making the sound and I had it fixed with shims on the spider shoes (or you can buy new spider shoes) and also had the center bearing replaced...after that, it idled smooth again.

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

I agree, a worn primary clutch sounds just like piston slap.

 

I was thinking the same thing but then I took the primary clutch off and reved the bike without it and its still knocking.The knock also never goes away it wether its on idle just trail riding or top speed cold or hot its really frustrating.Last time I had that problem it cost me $2500.00 and I dont want to spend that kind of money again.

 

Well it looks like its exactly what I tought the cams and rockers are gone again and my dealr wants to charge me another $1500.00 so what im wondering is if there is a place in Canada that I could maybe buy a used or rebuilt engine for about the same price.Let me know what you have please I cant trade it in with the motor gone in it they wont give me anything for it.

 

I had a knocking sound similar to loose tappets, noisy timing chain etc... turn out that a clip on my plastic was vibrating against my heatshield on my exhaust pipe and transmitted the sound right to the engine. You could have sworn it was the engine. Found it by accident one day by having some of the plastic off the machine and the sound wasn't there.... just like magic...

 

Yeah I wish it was a plastice rubbing thats making the noize but I had the top end taken out of the bike earlyer today and the cams and rockers are both used up and this is the second time since I have the bike that this has happened.

 

You should be able to find a used P650 or P700 motor on Ebay that is within your price range.

2nd time huh? I wonder why that is happening to your motor...did you have any overheating problems or perhaps run it without oil or something? Or did you not have the valves adjusted correctly? That seems odd to have that problem twice.

Good luck and happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]