You guys need to look at the design of a Trailblazer. It has two ducts leading to the clutch housing. One duct at the front is the air inlet. The other duct, positioned same as the sportsman duct, is the outlet. The fins on the primary move the air to provide a forced flow of air from the inlet to the outlet. The outlet is positioned on the left side of the cylinder to cool the engine when it is iding. Seems to me you need an inlet near the drive clutch similar to the Trailblazer.
Maybe this gives you some ideas
BryceGTX

 

bryce gave me an idea. what if a fan blade was monted directly to the primary clutch. the only probelm would be the fan would have to withstand rpms of 6000+. if it could it would really be moving some air. i have a junk grasshopper mower that has fans on top of the hydro pumps that are about 6 inches in diameter. those pumps turn pretty fast so the may work. i may take a look at it tommorow. hmmm...

 

It had better be attached well!!! Otherwise, your fellas (the family jewels) might get a piece of schrapnell surprise!! Ouch!!

 

Have you checked into a clutch kit. Along with performance increase, they offer less belt slippage than a stock setup. It should be more effective than a fan. Also look into a dayco belt, they are designed to help move air and keep the belt cooler. Plus a dayco slips alot less than the stock one. I am sure these quads have been designed with the heat in mind. I wouldn't worry to much.

 

Hey farmerboy.. Although you could mount blades to it, the inside of the primary clutch already has blades. Seems the Trailblazer mounts an inlet just behind these blades (on the engine casing). Then the primary clutch blades act as a centrifugal fan.
I hope this helps you
BryceGTX

 

thanks bryce. so if the primary has a fan, then there has to be an inlet and outlet to make the air circulate and cool. which the trailblazer has? but the sportsman only has an inlet. so...my head hurts from thinking bout this so ive decided polaris has kept heat in mind when they built it and it will be fine. whew!!...i can finally sleep at night

 

Hmm.. It seems that the Sportsman also has an inlet and an outlet. The outlet is the hose coming off of the top of the clutch housing. The inlet is a hose connected near the bottom left rear of the engine (800 efi, TB is front). So it seems you guys have a similar setup. Maybe I misunderstood.. It sounded as if you guys were saying that the air does not circulate.
BryceGTX

 

i just went out and looked. i couldnt see where an inlet would be. but just for kicks i took the hose off of the outlet and started it up. air started blowing out. so im not goin to worry bout it anymore.

 

Hey farmerboy. I just looked at the 500 HO drawings. There is a round tube that attaches to the lower crankcase. On the left side bottom of the engine. You will probably have a hard time seeing it. It rises up near the airbox front, maybe under the gas tank. This is the clutch air inlet. Your test was a good one.. it shows there must be an inlet!!
BryceGTX