142f 4-stroke no power

[Carbunckle]

So I bought this bike used got it all rebuilt an good to go I thought. Well it starts up but will only stay running with the choke on an at higher throttle and has Absolutely no power I've ripped the carb apart an cleaned everything I can think of. And I found a bunch of gas in the oil so I changed it and no difference anyone have any idea that could help me?

 

[Hunter]

How cold is it where you are? could be running lean

 

[Sidewinder Jerry]

So I bought this bike used got it all rebuilt an good to go I thought. Well it starts up but will only stay running with the choke on an at higher throttle and has Absolutely no power I've ripped the carb apart an cleaned everything I can think of. And I found a bunch of gas in the oil so I changed it and no difference anyone have any idea that could help me?

Just cleaning the carb isn't enough; you also have to know how to adjust the air/gas mixture.

 

[DAMIEN1307]

Just cleaning the carb isn't enough; you also have to know how to adjust the air/gas mixture.

As well as looking for air leaks as that would seem to be the likely cause if it only runs at full choke and high idle.

 

[GW's Motorized]

Sounds like an air leak or a clogged pilot jet. I've had the pilot jet clog on many small engines and they just keep re clogging for a while

 

[Chainlube]

Check for spark-
Check for compression-
Check for fuel=

If you cleaned the carb, the float needle could be stuck.

 

[darwin]

Try cleaning the IDLE JET. It's a black plastic jet located under the black plastic idle set screw. You need a fine wire from a metal brush to poke through the hole on the end of the jet. Be careful pulling it out, WD it and gently twist it out. Be careful with the oring/s around it. Try not to rip them. That jet if dirty will cause you to have all sorts of throttle issues. Oring leaking on it will do the same.

 

[meridianPeteJ]

Valve adjustment?

 

[darwin]

Valve adjustment?

Never hurts to check, could be the issue. Once checked, once eliminated.

 

[michael whiteman]

If you've followed everyones advice in the above posts, then you should be up and running. I drilled my #54 main jet .003 larger which helped noticably. Keep in mind I do not use an air filter and my muffler is of a straight through design. Both changes will necessatate this mod. Never the less, I did find the stock engine to run lean. No doubt to comply with emission laws.