Hi I am new here. I have a 95 2x4 400 was running fine. The other day was riding it and it had a loss of power i almost thought i ran out of gas. when i hold down the throttle it does not have full power. took the carb apart and cleaned it made sure al the lines were clear. but it together it will start om ether and it will run like crap. when i let go of the throttle it dies someone please help thanks.

 

Check compression,should be minimum of 100 psi. Also check reeds,could be broken reed petal,but usually a sign of piston seizure,excessive clearance,worn out top end when machine gets warm and then dies or looses power. OPT

 

Sounds like a piston seizure to me - did it just slow down and then die?

 

do a compression test first thing to see if it has at least 100 psi.

 

ok so i rebuilt the top end and the carb put it together started it up and it run like you are holdig the throttle wide open anyone know anything about this

 

did you put the carb back together right and make sure the slide is all the way down in the carb? is there a big air leak on the seals some where and sucking inalot of air?

 

OK so everything was running fine once i put it all back together, but last week i was riding and my 4 wheeler started to putter like it was running out of gas. got it back home started looking at it and every time it putters there is a cloud of smoke coming from the left side where the motor is i saw one of the nuts on the motor was loose. I tightened it started it up and is still doing the same thing. I checked everything and cant figure it out some one please help, it also sounds like an exuast leak but didnt see anything thanks