Motorcycle Repair: Chinese Scooters, air fuel mixture, needle valve

Question
Dear Sir,

I just bought a brand new DangFang Chinese Scooter, and it won't start. Each time I press the electric start it will engage for a few seconds and then quit. Every time I hit the throttle, it kills it immediately. And after a few attempts at starting it, I begin to smell gas that wasn't there before.

I tried adjusting the idle screw on the throttle, that helped a little, then I tried the air/fuel mixture, that didn't seem to help. This is my first bike and I am rather inexperienced.

Answer
Hi Michael,

If you have a fuel smell it may mean the engine is flooded with fuel.
This can prevent the engine from starting.
The first thing is to remove the spark plug and
see if it is wet with fuel. You may have to clean or replace
the spark plug. With the plug out the engine can be turned
over to try to blow some of the excess fuel out of it.
Be careful as raw fuel can ignite with any flame or spark nearby.

I would check the carburetor as it sounds like the float
needle valve inside is stuck or sticking. This allows
fuel to overflow into the engine and then it floods
out the spark plug.

Often the carburetor just needs cleaning or even just
a tap on the side of it may dislodge the stuck float needle valve.

If you notice fuel dripping from the bottom of the carburetor
that means the needle valve is stuck or leaking.

Once the fuel is cleared out of the motor it might start
with a new or dry spark plug.

Make sure your battery is fully charged as well as the electric
starter needs lots of power to turn the engine.

WS
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