not idling ??

[blompod]

Fired my new 80cc up for the first time today, starts easy but wont idle no matter how I fiddle with the mixture/idle screw, and dosnt run smooth at all. When i give it more gas it seems to bog down a lot then picks up but misses alot. What are the first and main adjustments to do from new, a starting point? thanks

 

[Dr. J.]

You probably have an air leak where the intake manifold bolts to the cylinder or where the carb slides onto the intake manifold. If you can keep it running while stationary with the clutch lever locked, spray carb cleaner around the intake manfold. If it suddenly increases speed or kills the engine, you have an air leak. If I were to guess, it is probably where the carb clamps onto the intake mainifold.

On all of my motor bikes, I install an o-ring on the inside of the carb where it slides onto the intake manifold. Make sure to shove the carb on as far as possible, then snug the car nut and bolt.

 

[blompod]

thanks I'll check that out, I did push the carby on as far as I could and clamp bolt nice and tight. started without choke too, I thought that might mean its too rich. But it was a very hot day here today, maybe it doesnt need choke in the hot weather. Air leak means running lean not rich hey? but that idle screw does nothing.

 

[Dr. J.]

Yes air leaks directly relate to a lean condition. Another thing you might check is the clutch adjustment. Your clutch may be dragging which will make it difficult for the motor to idle. What this means is the clutch is partially engaged instead of disengaged.

 

[try1897]

My bike has an 80 on it from Kings and after about 2 months of running good the thing started to not idel at all and would spit and pop sometimes. I discovered that the gasket at the bottom of the jug ( between the jug and bottom end) had indeed blown out. I made one and it worked for a week and while I was trying to get one from Kings (next to impossible) Smurfer came to the rescue and sent me a good gasket (heavy duty) and that fixed the problem. It idels fine. By the way thank you again Smurf I owe you big time. Check it out.....Tom in WV

 

[blompod]

would an exhaust leak at the head cause it to run like a pig? I had to do some serious bending of my pipe to make it fit and clear my front down tube on my bike. Its pretty kinked up in a few places. when running my bike for the first time it was spitting oil out of the exhaust gasket where it bolts on the the engine