read somewhere that you can measure the float height with the bowl full by sticking a rod down the bowl vent. apparently there is a special measuring tool that rochester made. any idea of what the measurement should be? my float has gotta be way too high, i'm burning fuel like a mutha. i know i can go thru the std adjustment with the top cover off, but this would be a nice way to "field test" it first
Float level isn't something that just changes unless someone took the carb apart and changed it. Excess fuel consumption can be caused by a number of things. Without knowing what you have, I'll generalize my suggestions. A choke that is not opening all the way is the most likely cause. Check your vacuum timing advance-it may be inoperative, cracked hose? Also, perhaps the metering rods are stuck in their bore-common problem with q-jets. The choke pull off may not be working. q-jets are famous for secondary well plugs leaking causing rich mixture. They make a repair kit for that. What is the application?:Smarty:
Mike, To my knowledge, you can't check your float level that way. If it was high, the engine would flood out. What you can check is the power piston. If you stick a small screwdriver down the bowl vent, you can rest the tip on the power piston. The piston is held up by a spring. This pulls the primary rods out of the jets, for a richer mixture. Engine vacuum overcomes the spring tension and holds the rods in the jets for a leaner mixture. When you stab the throttle, vacuum drops off, and the spring raises the piston, and the rods. If you put the screwdriver down the bowl vent, with the engine off, you should be able to push the piston down and feel the spring tension pushing it up. Then start the motor, and with the screwdriver in place, crack the throttle quickly. You should see the screwdriver pop up, and then drop, as the engine vacuum pulls the piston back down. The piston might be stuck in the rich position, or the spring may be damaged or the wrong one. This would give overly rich mixtures, and bad gas mileage.
i adjusted the float awhile back, and it seemed high at the time but it measured out. i remember making a fairly substantial bend in the arms and thinking that it was alot. since then the motor has run real rich its a stock 73 Century motor with the correct year qjet 4bbl thats transplanted in my jeep pickup. new choke pulloff and I've confirmed that the choke plate/hi idle cam step level system is functioning correctly Larry, thats great info and just what i was looking for, thanks. i'll do alittle testing with my screwdriver ala' your picture later today
