I just brought a 2000 Yamaha Big Bear/Kodiak 400 (only 1500km). I took it for a ten minute drive and it started to bog down. I took it to the dealer and they said it was bad gas and they cleaned the tank and the carb. I drove it 40 kms and it started doing the same thing, took it home cleaned the lower part of the carb and the tank yet again. Drove 40 kms same thing!! This also started to happen after I want in a little water. Took it back to the dealer and they said there was a little crap in the carb and I know the jets are clean because they cleaned them, but nothing that should cause trouble like I was having!! Any ideas would be great!