Motorcycle Repair: sheng wey carbi, float bowl, needle valve

Question
i want to no do they only have one idle mixture screw on them and how many turns should be set at wen i turn the fuel tap on it seems to run out of the over flow pipe as it is getting to much fuel

Answer
Hi Steven,

They have only one idle screw and if you set it about one turn out
and then warm up the engine before adjusting for the smoothest
idle.

If your carb is overflowing then you have a problem with the float
needle valve not sealing. It could be some dirt under the needle
or if it is very used a worn needle valve.
My guess in you have some dirt under the needle or
the float is not set to shut the fuel flow off into the carb bowl.

Sometimes a light tap on the float bowl will reseat the needle.
If it still leaks you will have to remove the float bowl
and float to check the needle and needle valve seat for problems.

It might even help to very gently blow some carb cleaner or such
down the fuel line to the carb.

Until you get the overflow stopped there is no use trying to adjust the
idle mixture. The bike will just flood and smoke and run too rich.

Your spark plug is also likely dirty and black from flooding.

WS
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