Bike doesn't rev right out

[matesrates]

Hi there i have a skyhawk 66cc know as f80 its got the larger 80cc carby on it when i'm riding at hign revs doesn't seem to peak out all the way....It does rev right out but its only on and off
Can anyone out there help????

 

[GearNut]

While I am not familiar with your exact engine, that sounds to me like a fuel starvation problem. Check for good fuel flow out of your fuel tank. If that is good, then check the float height setting in the carburetor to be sure it is not too low.
If all checks out well, then you are beyond my knowledge of your paticular carb.
I would venture a guess that the high speed fuel circuit may be a bit lean.

 

[matesrates]

While I am not familiar with your exact engine, that sounds to me like a fuel starvation problem. Check for good fuel flow out of your fuel tank. If that is good, then check the float height setting in the carburetor to be sure it is not too low.
If all checks out well, then you are beyond my knowledge of your paticular carb.
I would venture a guess that the high speed fuel circuit may be a bit lean.

Float height setting meaning that gold pin under throttle cable??
It is on the hignest setting its the larger Nt carby i think

 

[GearNut]

No. The float literally floats on the fuel stored in the carburetor's float bowl. As the fuel level rises, the float works on a lever that in turn works on a needle valve to shut off the flow when the float bowl has reached proper fill. If it is set too low then proper fill is never reached. This will lead to a starvation situation at high engine speed.

 

[stv1jzgte]

Float height setting meaning that gold pin under throttle cable??
It is on the hignest setting its the larger Nt carby i think

That may well be the problem, depending on the taper of that needle it may be blocking the feed tube at wot.

Check what GearNut has said if its still bad raise that needle 2 notches

 

[matesrates]

That may well be the problem, depending on the taper of that needle it may be blocking the feed tube at wot.

Check what GearNut has said if its still bad raise that needle 2 notches

What do you mean Gear nut???
where exzactly do i find this??
Thankyou

 

[GearNut]

While this thread does not pertain exactly to your issue at hand, Norman shows ALL the bits and pieces to these carbs, as well as making the carb happy.
Your carb may be a bit different, but the fundamentals are the same.

http://motorbicycling.com/f39/motorized-bicycle-carburetor-install-rebuild-302.html