The HO 670 makes good power. They dyno right around 130hp give or take a couple. I just bought a 99 Mxz HO 670 for $1,200 the sled was mint with under 2,000 miles. I sold the reverse kit out of it so I now have under $1000 invested in the machine.

 

So the 98 Summit X and the 99 summit X both have the 128 hp? I know the mxz ho had the 128, but wasn't sure about the summet x model??

I want the bigger engine! Which is why I wanna be certain of what im buying!

Thanks:c-n:

 

They are both 669 cc.

 

the 98 summit 670 is the same motor found in the 99 ho, they are different from the standard 670 in having a different ignition, porting, rotary valve, pipe, and compression. the motor was a work of art and the swan song of rotary development. they made 128 to 131 hp depending whos dyno they were on. power was a little peaky, you could feel it "come on the pipe and it wanted to pull your arms off. great torque. at the time it made as much hp as 800 twins and was considered a grass drag beast.
I had #247 of 400 toni hiekonnen edition mxz 670 ho, wish i still had it!
:buttrock: