Motorcycle Repair: 1965 Honda C110 runs rich, honda c110, honda 50

Question
Hi Bill,
I hope you can help me out.My 1965 Honda 50 runs rich.When the engine is cold it will fine for about 2 miles then foul the plug,black sout not oil.Once it is hot it fouls the plug on start up.I have tried leaning the carb.But it will not lean out.I put a carb kit in also.It idles fine but when you give it throttle it runs rough then it will smooth out at about 2,000 rpm,s.Thanks again Bill,Ken in NE  

Answer
Ken, float level should be 17.3mm... check float for pinholes that may cause it to partially sink raising the float level artifically. STD main jet is #82, #35 idle jet.
If you are using KEYSTER carb kit parts, I would see if you can find OEM parts instead.

Be sure that the compression is good. Valves set at .002.
Needle setting should be 2nd groove from the top.

Check ignition timing... .012-.014" should open them at the F mark... it is 35 degrees fixed advance.

Hope that helps..   Bill Silver