My buddy just bought a 2003 ZR900, and under full load, he says that he hears a ratcheting sound. I told him to make sure the track tension and alignment is good, he claims it is. I also said to change the belt, maybe there is a flat spot on the belt, and he claims the belt is good. Any other ideas?

Well if he says all those thing are good may be the chain or the drive wheels are worn. theres not anything else to check

His chain is ratcheting in the crank case. adjust it tighter, or it my need replacing.

I forgot about that, your right, the older sleds dont have the Diamond drive. I know how to adjust the chain tension, I will let him know. Thanks

Yup check the chain tension and drive bearings. The lower bearings are famous for failing.

If the speedometer isn't working it is the jack shaft bearings that are worn out.

I wont see this guy until Monday, I will be out riding while he just looks at his sled like is a trophy or something, but Gerry, before he bought it I made sure to have him check that it goes smoothy into reverse, and the speedometer works good. I am going to talk to him at work monday, and am going to take a ride over his house and check the chain tension. Plus, this guy doesnt really know much about sleds, I personally feel that he may have a flat spot in the drive belt that he doesnt realize is there. I will keep ya posted. My old polaris sled had the best setup for checking Chain tension, I hope the Cat is pretty much the same way.

Did he figure it out?

Havent seen him yet today, he is on the road tech, but if I had to guess he probably already made and appointment with the dealer. This guy doesnt try fixing anything on his own.

updated 12/29/2009- My buddy at work with the ZR900- Ratcheting is fixed.... It was the chain tension. Its got sort of an automatic chain adjuster, just snugged it about 2 turns by hand, tested, and no ratcheting. Thanks for your ideas.
Should he be concerned about the chain? Or is this a normal maintance procedure to tighten it once in a while?

From past experiences, you just hand tighten it. it's normal maintenance

I was going to suggest the auto tensioner but when I checked the parts diagram of that year sled it showed the old style bolt and lock nut. Just a suggestion I'd tell him to take that auto adjust unit out and replace it with the bolt and lock nut style.

he should install a new chain and sprockets if it has been slipping

He is going to take it for a good ride, and if it jumps again, going to dig deeper.

i will tell you if that chain breaks he will be buying new cases..when them break they do all kinds of damage thats why you allways replace the chain every few years