Hes right

 

thats a big engine your trying to fit in the warrior.... but anything is possible

 

Here is some numbers for you guys from someone who has done a Warrior motor swap. Warrior motor with carb and wiring is......125lbs!!!!! Yes that is right and it is huge. 400ex motor with a 440kit, 39FCR carb, wiring, and exhaust is 57lbs and much smaller.

Things that had to be modded

Motor mounts
oil cooler mounts
align the sprockets, not easy
oil tank has to be custom made as oem tank does not fit anywhere
exhaust tabs
header has to be custom made as the bends send the silencer up by your face. I had to cut, twist, and legnthen mine 4 inches to make it fit.
extensive wiring modifications
coil mounts

Now if you went with a 660r motor you have to add in the radiator and all that goes with that. After you mount the oil cooler and tank there is no room in the front for a radiator unless you mount it out in the open. Could use dirt bike radiators I suppose but may not cool enough, not sure.

My Warrior project took 8 months to complete from start to finish and thousands of cuss words and bandaids.

Its totally worth it!!!!!!!! Ended up being cheaper than boring to a 400cc.