My "new 400" November last year broke down about a month ago. No spark. I thought it probably would be the stator as my old 335 sp did a stator just after it ran out of warrenty. But after getting the dealer to check it, it was carelessly put together. They had jammed the igition lead under the fuel tank and it finally broke the core through and hence no spark. The dealer fixed it, but after a lot of stuffing around for him and I both.
Love the bike though, tore a rear inside boot a few weeks back and used a search on this site to find out how to put the new one on.
The 400 is a big improvement on the 335 sportsman. I did nearly 8000miles on the old one. The 400 has nearly 200 hours on it since November. It rides better, steers sharper, four wheel drive is 300% better, the previous outboard system was useless. It uses more fuel though which is the only thing I can fault, other than the standard tyres are S*** and I replaced them before riding it with 4 PLy rated tyres.

I would highly recommend this bike, extreemly stable and excellent in AWD.
Here in Australia our country is a lot harsher overall than the states and 99% of all quads sold here are used by farmers.
Cheers all
Scott