Widget,
A piece of advice here on these carburetors. Get it ultrasonic cleaned, regular carburetor cleaners can damage the delicate rubber check valves inside the carburetor; plus using an ultrasonic cleaner you don't need to remove the welsh plugs normally though I do remove the mixture screws.
A couple setting that comes to mind. One is the metering lever height, it is flush with casing. Use a straight to set this. Second the initial mixture settings is usually 1-1/2 turns ccw from lightly seated position. This is the Zama will start settings. You fine tune from there.
As for the compression test mention. It only tell only the condition of the cylinder, piston, and rings but will not tell if you have a crankcase air leak. This is what the pressure/vac tests are for. As pressure testing the carburetor, the test will only show if the fuel pump side is sealed and that the metering valve is leaking or not. You can not test the metering side.
One note if the metering diaphragm is stiffen it will cause problems is it will move as intended controlling fuel flow.
Added Note: If when doing compression test. You do it with the throttle held open. If you readings are @ 100 psi or less than you have a severely worn cylinder or stuck rings. From my experience it takes at least 100 psi for a 2 cycle to run correctly
Last edited by AVB; 30/09/19 11:11 PM.
