i just finished riding my 2002 bombardier 650 i was just crusing around with my nefew on the back, i never went faster than about 15 miles per hour, we road for about 30 minuets when we got back i notice a loud knocking in my engine, sounds like someones inside the the engine with a hammer trying to get out. im not losing any power and the quad still rides the same, can anyone tell me what can possibly be wrong with my bike.

 

It doesn't sound good to me the way you describe it. I'm not sure exactly what it would be, but I wouldn't start it again until you take the top end off and inspect everything. You don't want to risk any more damage.

 

Try removimg your engine chain slack adjuster. Use carb cleaner and blow out with compressed air.

 

I agree with OMR the first place to check would be the cam chain tensioner... they are known to lock up, and are relatively easy to check, and replace if you cannot free up the original.

 

were is the engine chain slack adjuster located.

 

On left side of motor, below carb, is a large 22mm or 7/8 bolt.
Remove bolt and washer.
Use needle nose to pull out plunger.
Clean plunger .
Clean out bore, that plunger rests in, with q-tips or lint free rag over blunt rod or philips head.
Spray bore with wd or lubricate with oil, re-oil plunger and re-install.
Re-install bolt/washer. Do not overtighten.

 

thank you omr for the advise that you gave me on the chain slack adjuster. i pulled out the plunger and it was stuck, i got it unstuck and oiled it up and it worked like new again, thank you so much i throught i was going to be coming out the pocket with big bucks for repairs. your the man.