ok, where is the power differance on these two motors? I know what makes them differant mechanically, now I want to know which is better low-mid-top?

 

Polaris claims a 20% power increase with the HO engine over the non-HO. Most of the power gain is top end, a little gain upper midrange, and an actual loss of low-end torque.
Parts that are notably different between them are the cam and carb. Keep in mind though, that the crank and engine cases, while having the same specs as before (as far as bearing size & piston stroke), they have been beefed up some.

There are some people, the ones who don't drag race, who actually prefer the NON HO engine. These guys miss the little extra low-end grunt and have no use for top speed. Mud boggers & rock-hoppers in particular. In addition, the older machines had EBS as an option, and the non-EBS clutches have a lower initial engagement ratio, allowing for still better low-speed torque.
Also, the non-HO was easier on gas.

 

when using a H/C kit they add weight to the center on the 500 but not thye HO, anyone have a theory on this?

 

It has to do with what RPMs the engine makes the most power/torque.

 

I have a 97 500 and a 2002 500 HO. I like the 97 a lot better and ride it most of the time. A lot of people like the engine braking, but it is not for me. The 97 is faster out of the hole and has more low end grunt. The HO will pass it and slowly pull away after about 200 ft and has a higher top speed. For real rocky riding and steep hills that have to be navigated slowly the non HO is much better in my opinion.