My KLF 400 4x4 sometimes will not start. I checked and it is getting no spark. It does not do this all the time just occasionally. The last ime it did it I took it to the dealer to get it repaired. When they got around to looking at it it started and ran. They said they could not tell what the problem is if it isn't doing it! It ran for several days then quit again. Does anyone have any ideas? I am leary to take it back to the shop.