Had my 03 900 out for the first run today.Very impressed with this sled.Pulled 7500 rpms at 90mph .Spins on snow cover lake ice like there's no tomorrow but it is one awesome handling sled.Just put the engine back together after truing up crank so never had a chance for a flat out run yet.My main question is ,the whining in the brake disk area,is this normal?Sounds like a 1992 mach1

Not at all normal, is the chain too tight or something rubbing? Another thought, jack shaft bearing on it's way out?

Only 1600 miles on sled and The jack shaft bearing is good.actually has a grease nipple on it.I will moniter the situation.I only put 6 miles on it since I purchased it.I had skid frame out,all clutches apart,installed reverse and a new track and just finished putting the engine back together after truing up the crank.I never even tried the sled out before tearing it apart.Now I know what I have.

Check the chain tension!

When you installed the reverse kit did you have the auto tennsioner fully retracted with it's jam bolt installed?

Yes I did.I have installed reverse on all my machines with no problems.I will check it out when I am off work Thursday.It seems to be more prominent at lower speeds as i opened it up for a few good runs across the small lake here and there didn't seem to be an issue.I know when you apply the brakes off and on you can tone it down.might not be anything.Can you run a manual tightener with reverse? I have never looked into it as i have never had an issue with the auto and i put some really hard miles on my 600 zrts.