Hey yall. Trying to figure out where to go from here... I have a 2004 Sportsman 400 that I blew the engine in (piston is cracked in half and lots of slop in it so I assume the rod bearing is shot too, and not sure what else). Trying to determine if I can / should / might pick up another engine used somewhere, and if so, is there different sizes / years I can check? Like will a 2004 700 Twin fit my 2004 400? Or will a 2001 500 fit my 2004 400? Any ideas would be great. Thanks!

 

Any 425 or 500 engine will work with the exception of the 425 Xpedition

 

Can't go with a twin they do not have the same trannies as the singles with a tranny/rear diff "all in one" combo.

The Fuji built singles 425,455, and 500 are the same motors with different bores and strokes but are identical from the outside.

I know a guy who put a 500 H.O motor in his 425 Sportsman no problem, he even uses his smaller 34mm carb without needing to rejet.

 

Good deal... good to know. Yall have any ideas on what year ranges will work? Like would it be 2000 - 2005 or what? Thanks yall.

 

1996 - now 2001 and up need larger 40mm carb ande intake boots for HO Alot more power with HO mods polaris claimed 20%

 

The Fugi motor never changed, all that change was the fuel delivery, Most have 34mm carbs ,H.O 500s have 40mm and some have EFI 39mm throttle bodies.

Like I said a 500 H.O or Non H.O will work with a 34mm. The H.O did not get all its power from a 40mm carb alone but also the addition of a High duration cam.

The EFI part is about the ATV not the motor, a EFI throttle body can be removed and replaced with a carb,easily.

Here is a PM I got.

He kept his 34mm carb with his new 500 H.O motor.

 

we started out with 2001 magnum 500, bored it out .030, put a wiseco 11:1 compression piston in it, did a little port and polish, put the HO cam in and a 40 mm carburetor, put it in our 97 425 magnum, haven't found a 500 that'll touch it

 

What do I all need to make my sportsman 400 05 into a 800ho
Cuz I got a bunch of 800ho parts

 

Complete engine needed along with the stator,flywheel and all the efi components,sensors,throttle body, injectors, complete wiring harness,exhaust system to start off with then modify the frame for the different engine mounts.It's a job,but can be done,but might be cheaper just to rebuild the 400,sell it and then get the machine you want. Or part it out on ebay or craigslist.