VintageBonanza Forum

[Bill]

I own a G35 with the E225-8 engine. The other day, I was cruising at 3000', power set at 23" and 2300 rpm, and I noticed the airspeed was decaying. I then noticed the fuel flow was down to about 7 gph; placing the mixture to rich did not help. This occured after a hot start in which I flooded the engine. After landing, I let the airplane sit and totally cool. The next start was completely normal, and I ran up the engine with normal indications. However, on takeoff the MP and RPM were normal; but the Fuel Flow was only about 10 gph. Any inputs would be appreciated. Thanks alot!

[Bonanza3941n]

I had a similiar problem on my 48 (E185-1). I ended up replacing the carburator because it was bypassing too much fuel. Don't do that unless your sure you don't have a fuel pressure "indication" problem. Connect a direct reading gage to your carburator fuel feed line and run the engine.

[Bryan Wells]

Can be several things causing the fuel flow problem. May not be a good idea to be flying until problem is located and fixed. What type of fuel flow meter do you have on your G35? I'll assume that your plane otherwise is original configuration with pressure carburetor. Do you have electric standby fuel pump installed too, does problem change when elec pump activated? Your take-off fuel flow should be around 21 gph. What are your fuel pressure readings during your event, do it fall also? What about fuel selector, is it possible that it is off detent or does the problem remain the same or right, left, or aux? So when has the carb been overhauled last and by who? What about your engine driven fuel pump, is it a Thompson or Romec? Have you been running auto fuel?

[doaspiras]

I fully agree. Don't fly till you get it resolved.

I own a K35 and had the same problem but during takeoff. Prior to takeoff the pressure and flow was good. No hesitation or nothing to indicate a problem. During takeoff, at about 300 ft above the runway, the engine pressure and flow dropped to nothing. Luckily the I was able to bring the gear down and land on the runway. Restarted the plane, no problem, but died 30-60sec later. We found after pulling the fuel pump, it was clogged with some rubber like pieces that was like mud. The fuel lines were all replaced recently, but one, the return line. After the pump was cleaned and return line hose replaced, she ran fine without a hitch. It's been 100hr since the incident, and you can bet I check the fuel flow and pressure like a hawk!

Fly Safely!

[Jim Aitken]

I had a fuel flow problem, turned out the inlet screen on the carb was partially plugged with fuzz.
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Jim A