Weights are only one of the factors in a clutching setup and we cannot tell you what will work without knowing the rest of your setup right now. Even then you will need to do some tuning yourself.

 

Weights just control your RPM. Lighter weights make it higher and heavier weights bring it down. If you want higher top speed then you need to change your gearing. If its an XCR 800 your talking about then you dont need any higher speeds. Just make sure everything is working properly and you will go 120mph+ all day.

 

Weights just control your RPM. Lighter weights make it higher and heavier weights bring it down. If you want higher top speed then you need to change your gearing. If its an XCR 800 your talking about then you dont need any higher speeds. Just make sure everything is working properly and you will go 120mph+ all day.

heavier will give you more top end because it will make your clutch close more.it might turn less but you have to work around it.make a mark with a felt pen on your clutch.if the belt goes to the top,then you have a good set-up,if not you have work to do.start with the heavier weights and work from there...good luck

 

Heavier weights typically hurt your top speed because the engine is basically being forced to do more work. I run heavier weights than stock in my sled because I want more off-the-line acceleration.
Once I tried 10-62 weights in my 600 and I lost about 5 mph in top speed (would only do about 95 mph), I put 10-60s back in it and I gained those 5 mph back.
Shortstop is right though, weights are only one aspect of clutching and you cant just look at weights. You need to look at the big picture of drive clutch spring, weights, driven clutch spring, helix and gearing.
One word of advice I would give is to change one thing at a time. Change 1 thing, try it out and see what it does. If you change several things at once, you really have no idea what component did what, so you have no idea where to go from there.