I've got a 500 Auto and one of my friends has an AC 400. I think its a '99. Last night we were riding, rather slow in rough terrain and I hear him whistle at me. I was in front. He yelled "somethings wrong". I pulled to the side of the trail and he pulled along side of me. His quad was coughing and popping. He tried to rev it up and it coughed, popped, and died. He hit the starter and it wouldn't start. We looked in the tank to be sure the gauge wasn't messed up, looked okay, 1/2 tank like ths gauge said. He hit the starter again and it fired right up and ran perfectly until we left the woods and parked.
Any one have this happen or have any ideas? The only thing I can think of is maybe he had gotten just a little water in the gas tank and it was just enough to act up for a bit. Comments?
Thanks, Gerry.

 

He might have had a kink in the gas tank vent hose and it would have airlocked, then when you looked so see how much gas he had left, you could have released it??? Just a guess assuming you took the cap off and looked in the tank and not just at the gauge.

 

It sounds like the arctic kitty might have fur *****. Put some fur ball treatment in the gas tank and see if the coughing stops.

 

Mine did the same thing the first weekend I had it, I swaped to the resrve tank and run it from there till all of the gass was gone. Problem,,,,,Moron put H2O in it,,,,He had a long hard weekend to reecover from the beating he got...LOL

 

I have a 400 and it has done the same thing on several occasions. I think I have figured it out it only happens when the tank is around half full. It is caused by the fuel pick-up, this is located in such a way that when the fuel level is down to around the halfway point and the fuel is bouncing around, the pick up can suck air. I have been keeping my tank full and it has not happened sinch although I have only been out on two runs since then. I also noticed that when you switch to reserve the problem clears up. This is due to the reserve pick-up location being on the very bottom of the tank, and is not as likely to suck in. If you have come up with any other ideas on what caused the problem let me know. I have also noticed that my bike will backfire when I let off the throttle at high revs.

Regards Jim Bell