Cracking Noise???

[017092]

I've searched the forums and couldn't find anything like what I've got going on. Long story short, always have noticed a slight cracking (like something was hitting the plastics) whenever I'm at slow speeds. Thought it might be chain slap. Checked around the chain and saw the front case saver was tweaked and was being worn down by the chain. Easy fix right? Put on a BCS case saver and thought that would do it. However, took the family to Glamis this last weekend and still noticed it. It's like a cracking/slapping noise and it I only hear it at low rpms, especially when it's bogging down in 3rd or fourth gear. I had my wife ride it and I couldn't believe how loud and noticeable it was, even from a few hundred feet away.

Engine sounds healthy in neutral at idle and when revved through all rpms. No weird noises. It's only at slow speeds. Any ideas???

[mikesr]

have you check alxe and swingarm bearings

[bad moose]

Timing chain slapping. It only happens lugging to 1/4 throttle? After that it goes away. Mine does the same thing, rotax's are noisy.

[017092]

I hope it's not the timing chain. I mean this noise is LOUD. Like I said, when my wife was riding it, I could hear it clearly from hundreds of feet away, over the exhaust. And it's not constant, even at low rpms. Sounds like something is breaking.

I checked the chain and it seems loose at the bottom, with a 2-3 inches of play (I don't have anyone to sit on it right now to check form the top). Could it be this?

There's only about 4 light rides on the bike, so I hope it's not the bearings either.

I appreciate the help and advice, but I can't believe this is normal sound associated with the Rotax. I will try to catch it on video and attach that.

[bad moose]

Take a motorcycle strap from grab bar to axle and adjust chain that way, no need for a second person. The other thought is how are your shocks adjusted? If not enough preload the plastic covers rattle.

[017092]

Nothing's been adjusted. Still the stock set up, I think. Just bought it from a friend who rode it a handful of times. How much should I tighten the strap? Until the shock bottoms out? I've read in other threads about tightening the chain with a screw driver and rolling the bike, so I will start with that. I guess I will throw the knobbies back on afterwards and see if that was the problem. Thanks guys, I will keep you posted.

[bad moose]

Sit on bike and tighten strap. I try to get the suspension at it's longest, about midway to just over on the shock.

Lift front wheels off ground to droop suspension a see if springs are loose, if they are tighten preload a little bit.

[blaster99]

I adjust the chain without a rider on the quad, I feel that it is close enough to the same tension. You can lean on the grab bar and check the tension with weight on the quad if you want to. Also the noise is more than likely either the chain slipping, or dirt getting between the chain and sprocket.

[fxracerx450x]

I believe its chain slap. I get it all the time usually I just down shift and give it some revs and it goes away. But if I don't the chain derails. I'm replacing my chain and sprockets once Renthal gets the sprockets avaliable to the public since they are supplying the can am factory with them right now.

[Blizzard24]

I see you have the X package skid plate on the quad, when I ran one the chain slapped it a lot and made a horrible noise, I switched over to a rotor/sprocket guard combo and never had another noise