case dex carb issue

[4160]

I've a case dex with a zenith carburettor and it only runs on full choke ,,once released it dies off straight away..the needle and mixture screw are about 1.5 turns off the seats..ive cleaned it thru but not making much sense of it

it will catch and fire on no choke but literally runs for 3 or 4 seconds and stops,but holding the choke on will keep it running as such but obviously abit rough

any pointers??

 

[Tgrasher]

Not familiar with your model but you have a classic case of not getting enough fuel. Easiest to start with checking the flow of gas out of the drain at the bottom of the carburetor. There should be enough flow to half fill a pint jar in 30 seconds. If not, check flow to carburetor, then start checking back up the fuel line to the tank, filter, sediment bowl. Good flow to the carburetor often means the cavity before/under the needle valve has a piece of dirt partially blocking the flow.