I recently bought a 10.4 kit for my 04' zr900. The instructions say nothing as to whether or not I am to transfer the metal plates on the outside of each sheave to the new sheaves. The holes are cast into the new sheaves but they are not tapped out to receive the screws. The plates I am referring to cover the "fins on the outside of the clutch sheaves and are held on my about 9 torx screws per. anyone know?

The screws that hold the windage plates on are self tapping. I personaly leave the plates off for better cooling.

I think i'll take your advice and leave them off. Although I don't think it would hurt to put them on. The 10.4 alone is going to allow this thing to operate much cooler. Thanks for the reply.

Why are they there?? What purpose do they serve??

Windage plates help reduce drag when the clutch is spinning. If you do a lot of rideing in deep snow leave them off. Put some red loctite on the self tapping screws if your putting them back on.

So for the guys that have the 10" secondary, leave them off to help it cool better. And everyone with the 10.4 update can put them on for less drag on top end. The 04 & 05 secondaries on the Diamond Drives were 10" and were known to skip/chug and heat up the sheaves when the sled went into overdrive. I'm not sure if the firecats had the same problem. Might just be those torque monster 900's

The problem with earlier secondarys was piss poor alignment from the factory and crappy shifting. Resulting in hot sheaves and blown belts. Some 10" clutchs never had any problems. A Shift Assist is a good cheap fix to add to any Diamond Drive.

Opps! Damn near double post.

I went with a bikeman torsional conversion to remedy the spring bind. Got it off ebay for $100. There's one on there right now with a "buy it now" $75 but I agree, the $20 shift assist is a must have for any dd. I wish they would just bring the old secondaries back. The only nice thing about the dd ones is the easy deflection adjustment. Do then newer ones have the spring pressure adjustment or are they a fixed setting?

Fixed. Another bright idea lol. All the aftermarket kits go back to the old style for fine tuning.

You have to wonder sometimes what their thinking is. So now you have no adjustment of the spring in the secondary at all. You have to take the spring at what values it is and run it. The only way to change it is buy a different spring every time you want to experiment. NICE!! It's almost as if they are doing everything they can to keep ppl from being able to tune their sleds.