the new 4 cylinder rx-1 snowmobile engine with EFI is pushing 150 hp,
an xcr 800 TRIPLE polaris like mine is putting 155 hp with STOCK carbs,now,
it has 225 hp with stock jugs just race porting and 14.1 dome heads,not to do a shame of me but the fact is fuji 2 stroke motor
are very potent when it come to power,if i had the case ported
i should got another 7-8 hp from it,and i still have stock ignition tough and flywheel,triple 2 stroke will always rule in the sleds market,just my 2 cents!

 

exept for turbo charged 4strokes, those are fast too

 

the botom end of my motor needs berrings, so now i am serous about the streetbike engine or snomobile engine, do you think that a sled motor will run hot, that is they only problem with snomobile motor, and the problem with the bike engine is that it will be very tall and i don't want to chop the frame very much. pluss i want the scrambler to look kind of stock if possable, what engine do you think will be better, i think that a 4-stroke will be better, but 2-strokes have given me bad luck lately.

 

it might be a tad on the expensive side, since you can only really get these things new, but have you considerd a Fusion 600 H.O. motor? its not that much larger than the 500 currently mounted in scramblers, its a paralell twin, fuel injected, aluminum block, 2 stroke, and uses the same belt drive, so the transmition could be kept.

not to mention the engine Dyno's out at 120+ horse power

 

Generally speaking, IMHO, I don't think that a snowmobile engine runs any hotter than other comperable engines. The difference is that the sleds have a radiater that is cooled by snow that is thrown off of the track (as opposed to cooling fins on an air cooled engines). Couldn't you use a radiater with an electric cooling fan with the sled engine?