I'm working to purchase a 2014 or 2013 Polaris sportsman 400 since the 500 isn't in the 2014 lineup. SO... I was thinking, if I read right the only difference between the 400 and 500 is the 400 has a 36mm carb whereas the 500 has a 40mm carb which provides more air and gas thus more power (I think im right there). Now if im right I can put the carb of a 500 on a 400 making it a vamped up 400 the equivalent of a 500. If anyone understood what I said what do you think? Yay? Nay? Stupid idea what are you thinking you idiot?

 

Bore is smaller on the 400,the stroke is the same on both. 455cc versus 498cc on the 500. If you're wanting to try to convert a 400 to a 500,no you can't just by changing carbs. If you want a 500 find a left over 2013.http://www.powersportsnetwork.com/en...2=373726&go=Go
To further confuse you check the msrp on the 2013 500 versus the new 2014 570efi.More incentives on left over 2013 models to drop the price,but the msrp is only 300 bucks different.http://www.powersportsnetwork.com/en...2=373731&go=Go

 

Won't work, find left over 500, I'm stupid. Thanks!

 

Dont be afraid of a 400, they are only 5hp less, and just as torquey.

 

You can put the 40mm carb on the 455 if you also change the intakes to motor and air box.
I know a guy who went the other way. He put a 500 H.O motor in his 425 Xpedition (Also same motor) but he used his 34mm carb from his 425. Worked out and not even any re jetting needed.

I do not think you would notice much difference with a 40mm carb, the 500 H.O performance increase was more due to the high duration cam from the Scrambler in 2001.
Your new 455 Sportsman will have that cam already installed.

Not sure if it's even that much of a hp difference.