Arty
Well-Known Member
After doing numerous modifications to my China Girl, including ignition, porting, piston, fuel delivery etc., I just could not get my bike to run properly. It was way too hard to start, and if you could get it to start, it would run for an unreliable period of time, begin to refuse to idle down, then usually stop, etc. etc..
After endless hours of back-pedalling and re-checking my mods, in desperation, since I couldn't think of any other possible trouble source, I took apart the fuel petcock. - There was a tiny flake of metal embedded in the rubber seal of the petcock - and I mean small - way less than the size of a pin head. It must have been just the right size to let a small quantity of fuel through at times - and at others to block it completely - allowing the engine to run once in awhile, and leaning it out and starving it at others.
I think the flake was probably a tiny piece of zinc from a 1/4inch galvanized elbow in my fuel line, that flaked off when I tightened the elbow I had added during the course of my modifications.
Anyway - what a relief to finally find the problem.
Another hard learned lesson about a rule I already knew - but ignored., - - ONLY DO ONE MOD AT A TIME.
So - just a heads up - those fuel petcocks have really small internal passages, so any little piece of foreign material can cause a problem.
Also, I noticed that because of the design of the petcocks that come with the China Girl kits, unless you have the Shut-off lever exactly lined up with the "OFF" marker on the petcock body, the fuel can still get past. The stops on the valve only work for the "ON" position, not the "OFF".
After endless hours of back-pedalling and re-checking my mods, in desperation, since I couldn't think of any other possible trouble source, I took apart the fuel petcock. - There was a tiny flake of metal embedded in the rubber seal of the petcock - and I mean small - way less than the size of a pin head. It must have been just the right size to let a small quantity of fuel through at times - and at others to block it completely - allowing the engine to run once in awhile, and leaning it out and starving it at others.
I think the flake was probably a tiny piece of zinc from a 1/4inch galvanized elbow in my fuel line, that flaked off when I tightened the elbow I had added during the course of my modifications.
Anyway - what a relief to finally find the problem.
Another hard learned lesson about a rule I already knew - but ignored., - - ONLY DO ONE MOD AT A TIME.
So - just a heads up - those fuel petcocks have really small internal passages, so any little piece of foreign material can cause a problem.
Also, I noticed that because of the design of the petcocks that come with the China Girl kits, unless you have the Shut-off lever exactly lined up with the "OFF" marker on the petcock body, the fuel can still get past. The stops on the valve only work for the "ON" position, not the "OFF".
