First off, howdy ATVConnection.com forum folks.

I don't know much about engine work, just maybe enough to get myself in trouble. I've changed the air filter, oil and gear oil regularly that's about it. All I can say is on my 2003 Big Bear 400 4x4 dies every time I attempt to simply accelerate. Knowing a little about working on engines and what to listen for I figured it was a carb issue. Not sure? All I know is if I hold my hand about 2/3 over the intake tube that goes to the filter box, the engine doesn't die and I can drive it around.

I'd appreciate an tips or suggestions before I go take it into someone that may charge me $150 to turn a few screws. At least get myself educated on what the problem may be before hand. Thanks folks.

J.R.

 

Sounds like the air to fuel ratio is off. I would look at the carb for sure.

 

welcome to the forums, was it always like this? if not when did it start doing this? it sounds like its getting to much air not enough fuel, running lean on fuel most likely, so either carb needs cleaned, rejetted or the idle and fuel screw need to be adjusted correctly.

 

Check the carb vent tubes for kinks and blockage. If you ride in water alot, you could have mud in them. Drain the float bowl, and change fuel filter.

 

Yeah, something is restricting the fuel flow. You have to find out if the restriction is on the inside or outside of the carb. Check the vent line, fuel line and petcock. If all of that is clear, you might just have some trash in your carb.

 

I know it wasn't an ATV but I had a Honda 1100VT that was doing about the same thing. It was a dirty carb and I added some Sea Foam in the gas and it helped it after a couple of tankfulls were run throu it.