Rich,
Fuel blockage ?
Go through the fuel system from the tank(rust specks?),clean the tank filter,blow the fuel lines,check the motor fuel filter(if you have one) and the carbs for dirt.
I had grief several times in mine with very similar symptoms and it took my mechanic several goes to fix it properly.
Not a confidence building feeling to be flat bedded home !
Alternately,maybe a bad tank of gas ?
Cheers,
Dennis.
