My 22R Aisan carburetor suddenly started running rich at idle and part throttle. Engine dies at idle and runs rough at part throttle. It clears up when given more throttle but probably still running rich.
Turning the idle mixture screw all the way in helped a little. I had to set the throttle plate further open to keep it running (roughly) at idle speed. I can see fuel dribbling out the primary center venturi when running. Choke is fully open and fuel level in bowl window is good.
If it had a diaphragm for the power enrichment valve I'd suspect a torn diaphragm but Aisin power valve design doesn't have a diaphragm.
Any suggestions before I blindly start tearing into it?
Turning the idle mixture screw all the way in helped a little. I had to set the throttle plate further open to keep it running (roughly) at idle speed. I can see fuel dribbling out the primary center venturi when running. Choke is fully open and fuel level in bowl window is good.
If it had a diaphragm for the power enrichment valve I'd suspect a torn diaphragm but Aisin power valve design doesn't have a diaphragm.
Any suggestions before I blindly start tearing into it?