Hello, looking for help with an OLD yale forklift with an inline 4 Mazda VA gasoline engine. forklift will start and idle. idle is a weak low idle. touch the throttle and it dies. has spark. have checked timing with timing light. has 150 PSI compression on all 4 cylinders. have used carb cleaner to see if it would accelerate with more fuel and it does not go above idle.
Have installed new points and condensor, and rotor, cleaned the cap. installed new ignition coil. Completely cleaned the carburetor and all the jets- which looked very clean and no sediment in the float bowl. I verified the accelerator pump, gives a squirt of gas with throttle movement. if i crank engine holding throttle wide open there is fuel flow from the main jet.
I have played with a vacuum pump to check the vacuum valve operation below the carburetor- assuming this is the governor or backfire devise? i can hear it click closed when it dies- so i believe it is opening correctly. i even took exhaust loose thinking the muffler could be plugged and no change. I am baffled. is there another governor somewhere that would restrict fuel or air? This was running excellent till it was shut off. At next start up it just idled. I can not find a manual for it.