I have a GCV160 here starts ok on full choke but the slightest attempt to move off choke and it stops. Normally I would just rip the carby off and put it through the ultrasonic but I think there is something else going on. I have checked the valve clearances and they are fine. What concerns me is that when pulling this motor over there is an unusual "choofing" noise coming from the exhaust or maybe head gasket. Any thoughts?
Ok I am obviously doing something wrong. I have put a number of Honda carbies and Briggs as well through the ultrasonic cleaner, clean the emulsion tube, main jet and blow air through the jet on the top of the carby. Some carbies are fine after this but I still get a percentage of these carbs that usually still hunt. I know if I put a new carb on it it will work fine, I am just curious as to why these carbs do this. Is there something I am missing?
You could use a cheap can of brake cleaner ,Boston 300g Aerosol Brake Cleaner $7.50 ,you may need to drill the cleaner nozzle and push in the small plastic tube from a WD40 can , then spray that into all the orifices to make sure they are clean.
Sometimes I need to use fuse wire to clean a jet back to original size and sometimes you need to push an oxy tip cleaner through if a pilot jet etc won't unblock after cleaning.
I have heard some people say the only thing after cleaning the carby that stopped the surging was to increase the jet size.
Most of the time the surging is the blocked jet on top (pilot jet)
I've been meaning to try Acetone overnight but as we know What NOT to Soak
Rubber parts (gaskets, O-rings, seals) – acetone will swell, crack, or dissolve them.
Plastic pieces (floats, choke housings, etc.) – may soften or melt.