Just a general question from a non-Polaris owner.

I am curious about big bore kits for for the 400 and 500cc motors. How big can you guys go? I mean, there's lots of stuff out there for the rice quads, but what about the Polaris motors?

There HAS to be something out there. Does anyone know? Should I be afraid? Very afraid?


------------------

 

As far as the 400's are concerned Aaen and HPD offer what they call their 440/Big Bore Kit (an 88mm forged Wiseco, stock is 83mm), although it think it actually measures 421cc. Considering the 400 is actually a 378cc, that equals about 43 more cc's over stock.

Don't know much about the 500's.

------------------
Jerry Goodman '99 400L, '98 TBlazer

 

About a year ago Dirt Wheels ran an article on a Sportsman 600 with the bore & stroke increased to 600cc. Four Stroke Tech did the work.

 

Thanks for the correction. I was always curious why they caled it a 440 if it only measured 421. 438 sounds a lot better.

------------------
Jerry Goodman '99 400L, '98 TBlazer

 

88mm on the 400 takes you to 438cc. 87.5 gets you 421cc. If you want to compute it yourself, here is the formula:

bore (88) squared (88x88=7744) divided by 4 (1936) times pi (use 3.14 if you don't have the value on your calculator, 6082) times bore (6082x72=437912.88) divided by 1000 = 438cc.
Scott.