Has anyone else noticed that polaris is advertising their 07 120 as 8hp? 8hp from 121cc's? I checked several other sources and found the same numbers. My polaris dealer cannot confirm it, or buy a complete engine. I was told that there was a change in the 06 motor mid-year, but nobody seems to know what the change was or what the hp was for 06. If anyone has any thoughts or answers, please enlighten me. It seems like the people that should know, don't or aren't telling.

snowman336

I checked with the local dealer and he was unable to confirm it, so he checked with his supplier, who checked with his contact etc...
He eventually got info from some "testing" dept. at the factory who stated that there had been no change in the engines. It sounded legit.
So I just bought a new '05 for the same price as I see used ones going for, picking it up this wknd. Kids don't know yet, can't wait to see their faces.
Have a good one...
DVO

I was aware of 8hp listing. Logically I feel it's a mistake, if 8hp was available in 120cc after market guys would be doing so instead of selling bigger engines. Friend has an 8hp Robin, I don't know cc but engine is a lot bigger. Polaris had them governed for 8mph and possible the numbers got mixed up?

Have fun :div20:

yeah im thinkin 3-12 - 4hp tops out of the stock engines and i am beeing considerate

look at the bore and stroke, then go to honda page and compare, if suzuki found a way to get twice the hp out of the same engine everyone else gets 3 out of then they should start building car engines or something

dan

Got word back from Polaris. They gave no numbers and all they said was "were not offering the 07 motor". Whatever that means. I did see that AC is claiming 6.5 hp from their 119cc. Who knows. Right now were just going to rebuild the stock motor with a govenor spring and hi rev valve springs. We may eventually upgrade to a Robin 6hp from rec motor with a lighting coil, but we'll see what this motor does first.

snowman336 :fluffy:

DVO-Thats awesome! The kids will love it.
Thinksno-The robin 8 hp is 238 ccs and is physically huge. Also, I installed your revised suspension design. thanks for posting! I went one step further, cut off the spring stops completely from the front arm, and welded on mounts I fabbed to hold indy 500 spring blocks. Now I can adjust spring preload to complement the increased compression and rebound dampening. I havent been able to FULLY evaluate the function of it yet, but if you are interested I'll try to upload some pictures. Total cost was about $12 more than the upgrade you designed.

Thanks everybody for the responses. Snowman336

snowman336

Let us know how the adjusters work! Upload the pictures would be great. :div20:

Just to bring this back to the top. Not sure if you guys know now or not, but the Polaris 120 engine now has a different piston in them. It was a change from 06 to 07. We had to have the new piston OKed for racing and it has been approved. It is a little heavier and has a different top on it. Not sure how much more performance it has but there is a difference. I am rebuilding my 120 engine and replacing the old piston with the new....

Seems odd that you double the HP with just a different piston.I would think the carb would have to change also