125cc 4 strokes coolster pitbike carburetor problems.

[HuskyR]

Hey guys, I'm new to this site. Since I bought my pitbike 7 months ago I have had to run it with the choke on, all the time. I tried to adjust the carburetor with the choke off. But it just turns off. If I keep revving the engine it won't turn off. Also when I get to third/fourth gear it sounds like I'm on the rev limiter. It's just backs fires like crazy when I gas it. That's only with the choke off. Another thing it lacks power, I tried to do wheelies and it just doesn't come up. When the choke is on, it is just like a normal bike, and I can even do power wheelies in second.
Hope somebody knows what could be wrong.

 

[Cordogs]

I'm no Spanner Spinner but it sounds to me like an air leak. Is the bike brand new?


Try starting it up and spraying some WD40 or similar around where the intake manifold, engine and carb meet Keep the revs at or around 1500 rpm, if you notice the bike start to gargle n die when spraying pull em apart give em a good clean and try again. You may need some gaskets?
Worth a try before you start pulling jets out

 

[my67xr]

Welcome to Miniriders.

does the engine hesitate when you blip rev it ?
there might be a blockage in the pilot jet, or pilot circuit?


have you ever adjusted the valve clearances ?
they need doing every now and then.

what about setting the idle mixture screw ?
how many turns out is it from fully done up ?


make sure you drop by and say hello in our Introduce Yourself too

cheers, craig

 

[HuskyR]

I'm no Spanner Spinner but it sounds to me like an air leak. Is the bike brand new?


Try starting it up and spraying some WD40 or similar around where the intake manifold, engine and carb meet Keep the revs at or around 1500 rpm, if you notice the bike start to gargle n die when spraying pull em apart give em a good clean and try again. You may need some gaskets?
Worth a try before you start pulling jets out

I bought it new, from powersportsmax down in Cali. I made sure to go through the brake in period so the engine would not be damage. I will spray some wd40 into it, so any bad fuel gets blown through. I think your right about an air leak, so if it continues I will buy a new carb and a new air filter, and hopefully that solves it. Thanks for the help.

 

[zwebx]

I had a pitbike that was a turd to start, only ran on choke and ran quite well on full choke almost to the point where it was perfectly rideable but gutless and wouldnt rev to the redline and popped and farted when you were there..

Ended up being mud in the ignition causing a weak spark.. replaced it and now the bike starts 1st kick and almost threw be off the back when i first rode it (did not expect the power)

Dont rule out a bad spark.. Not yet the plug should be changed to a ngk before anything and it should be a strong blue spark

 

[gottagetacheaperhobby]

with checking for the air leak, start your bike up, let it warm up, and then spray your wd 40 etc around where your carb bolts to your manifold, and your manifold to your head. If your rpm change at all then you have a air leak in that spot and need to replace your gaskets.

 

[Goodolddays345]

The booklet is wrong, the choke is the opposite direction. I'm too late to help you but if someone is having the same issue maybe this will help.