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Fuel Consumption

RFSchaller

Well Known Member
What are you guys seeing for fuel consumption at cruise? I?ve got a little over 800 hrs on my 912ULS and have seen the the burn rate creep up from4.5 GPH to 5.1 GPH at 4200 RPM AND 22? MAP over the last 300 hours. Is that what you guys are seeing?

Rich
 
Are you running Mogas, and has it lately been winter blend? You will use more fuel in the winter time than summer time, air is more dense due to the lower average temperatures.
 
Our fuel burn was considerably higher than what others reported. During our last CI I did the carb inspection, which includes replacing the metering needle, float valves, etc. We also found a bad left choke cable that may have been keeping the left side starting carb from shutting off completely. Afterward our fuel consumption dropped by at least 1/2 GPH in cruise. We'll never know for sure, but think at least part of that was from replacing worn fuel metering parts.

About the only time I see 22" MAP is during descent and in the pattern, though. Couldn't tell you what the fuel consumption is then.
 
Our fuel burn was considerably higher than what others reported. During our last CI I did the carb inspection, which includes replacing the metering needle, float valves, etc. We also found a bad left choke cable that may have been keeping the left side starting carb from shutting off completely. Afterward our fuel consumption dropped by at least 1/2 GPH in cruise. We'll never know for sure, but think at least part of that was from replacing worn fuel metering parts.

About the only time I see 22" MAP is during descent and in the pattern, though. Couldn't tell you what the fuel consumption is then.

Dale, what is MAP on take off and initial climb? Doug
 
Dale, what is MAP on take off and initial climb? Doug
Have never noticed, to be honest. On takeoff and climb I have the throttle wide open, eyeballs outside and occasionally glance at airspeed. If I EVER get to fly again (it's been a long, long month of cr@p weather here) I'll try to get a look and remember what it is.
 
I?ve got a little over 800 hrs on my 912ULS and have seen the the burn rate creep up from4.5 GPH to 5.1 GPH

At 800 hours I'd be tempted to replace the needles and needle jets in the carbs.

Cheap and easy, and a prime suspect if you are seeing increased fuel consumption.
 
Andrew, I had my carbs overhauled at about 500 hours.

Did they replace the needles & needle jets? (Probably, but not necessarily.)

Last 200 hour carb inspection on my Rotax was 400 hours, the comment was they'd maybe replace them next time (600 hours).

Even so, your overhaul was 300 hours ago... the manual calls for inspection every 200 hours. It could be worth a look.

Or maybe your flying style has changed? Air filters excessively oiled?
 
Andrew, I had my carbs overhauled at about 500 hours.

Rich

Rich, nice getting all those hours in, dang that?s roughly 95 bbl of gas. They?re making overtime in Houston to keep up with the demand. Good on ya!

Not sure if Bing auto adjusting capability is less effective at your higher MSL with time in service than here at 500 MSL. What design parts have wear factors that allow it to auto adjust?
 
Andrew,

The west coast shop who overhauled my carbs did replace the needles and floats, but frankly I was not happy with them. They managed to swap my right and left choke assemblies which made starting almost impossible. Took me a few hours to figure it out and swap them back. As Gomer would have said, ?SHAZAM, now it works!?

Rich
 
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