by bgsengine » Thu Dec 19, 2019 3:10 pm
and how long has it been run since? Possible crankcase still loaded with excess gas, too. Also, operating engine with all blower tubes fully attached? Any adjustments need to be made with all OE tubes in place, they offer up the load (blowing air) and if they are not in place or altered, engine performance will suffer. Also, pressure test the fuel system? (may have a bad fuel tank vent that is allowing too much pressure build-up in tank - perhaps try it with tank half full and fuel cap off?) finally, with air cleaner off, look into carb bore at the throttle valve and rotate to wide open - when fully open, the hole in throttle rotary valve should line up perfectly all the way around with the machined bore in the carb throat. If not, you may have lost the lift roller (very tiny, just 1mm diameter, easy to lose if carb is taken apart by someone that doesn't know it is there) also the low mix adjustment needle, that's a very tiny adjustment screw that is right down the center of the rotary valve (many do not know that, and try to adjust the idle stop screw instead) and finally, obviously air cleaner can affect things - even one that "looks" clean visually can be plugged (same with fuel filters, by the way)
just a few other points to consider..
How poor are they who have not patience. What wound did ever heal, but by degrees? - Iago (Othello Act II, Scene 3)