i have a 2005 yamaha big bear 4X4
it is cuttign out when it runs it will run on choke it will idle fine but when you give it gas it back fires back through the carburator and pops the carburator off the intake. Pulled plug and spark plug is black. and then pulled carburator apart and cleaned and that didtn help either what do i do ?

 

my bb always does that when im out of fuel, so you must have a fuel problem. make sure none of your fuel lines are getting pinched between things because that is what happened to mine when it started cutting out.

 

Hello, I just bought a Yam. big bear 400 '05 for snow plowing And for hunting use on the side. At first it kept stalling out right from the showroom. WHEN I TALKED TO THE DEALERSHIP GUYS, THey said it usually has to go through 3 or 4 tanks of gas to break it in and it should stop. Also I only 3/4 choke it and it idles high for 1 or 2 minutes in neutral then I unchoke it and it runs well without stalling again. At first, this process didn't work that well but I'm on my 2nd tank of gas and it's doing better all the time. Good luck! PS> what Makes anyone decide to buy the big bear 400 yamaha? It is touted as a workhorse and because of manual shifting and METAL gears it's a more reliable worker for my residential, driveway/sidewalk snow plowing. Let Me Know!