grubbat
Well Known Member
Pulled the RV-9 out to make a quick trip over to 08A to pick up spouse. Only a 35min run and is a no hassle uncontrolled airspace trip. Cranking produced a weird stumble but eventually ran ok. Runup was good and apparently leaning out during run up cleared the plugs. Taking off and during climb out I noticed 30 gph fuel flow. What? Normally I’m in the 18-19 gph range. Yes my motor puts out some hp on takeoff thanks to the CS prop and other mods but not 30gph. I was supposed to be at 08a at 5 pm but decided that the rough running and high gph were the only clues I was gonna get so came back around and landed and cut everything off and reset the EFIS. Maybe my fuel flow gauge is defective ? I restarted everything and fuel flow was a little high but seemed to be better. Taking off I noticed my fuel flow climbed up to 22gph. Better but Not normal. Back around I came and landed. Hot and sweaty and late, I reluctanty got out (older folks know how difficult this can be at times. You younger bucks won’t understand) and realized that had I ignored all the warning signs, I’d would have been a NTSB report.
I had a fuel servo leak and thus the stumble when first cranking and high fuel flow. After decowling , the fuel leak wasn’t a broke fuel line or loose fitting. Get this, it was leaking out of the lean cut-off area on the precision fuel servo. The lean lever assembly is attached with two small screws and upon removal, the oring was not sealing. It appeared to be dry and brittle. Granted I haven’t flown the RV in a month , that oring shouldn’t have dried out and broke. or should it? I built motor like yesterday (actually 2015) and quick math says it’s been 9 yr already. Where has time gone. Also, I’ve Never ran auto fuel. This is what ethanol does to o-rings. How did it break? I guess it’s just par for the course. Maybe why they want stuff overhauled every 6yr?
I called up Don at Airflow Performance and he has me fixed up with an O-ring. I can’t say enough good about Don. He helped me with the injection nozzles on my Lycoming and has always been available to help me and as a result I send all my work and even my certified stuff to him. He’s the real deal.
Nevertheless, I wanted to share this broke o-ring situation to the brain trust at VansAirForce to encourage everyone not to get in hurry, to listen to your RV and pay attention to the high dollar EFIS avionics we get to put in our planes. Don’t be a NTSB report.
I had a fuel servo leak and thus the stumble when first cranking and high fuel flow. After decowling , the fuel leak wasn’t a broke fuel line or loose fitting. Get this, it was leaking out of the lean cut-off area on the precision fuel servo. The lean lever assembly is attached with two small screws and upon removal, the oring was not sealing. It appeared to be dry and brittle. Granted I haven’t flown the RV in a month , that oring shouldn’t have dried out and broke. or should it? I built motor like yesterday (actually 2015) and quick math says it’s been 9 yr already. Where has time gone. Also, I’ve Never ran auto fuel. This is what ethanol does to o-rings. How did it break? I guess it’s just par for the course. Maybe why they want stuff overhauled every 6yr?
I called up Don at Airflow Performance and he has me fixed up with an O-ring. I can’t say enough good about Don. He helped me with the injection nozzles on my Lycoming and has always been available to help me and as a result I send all my work and even my certified stuff to him. He’s the real deal.
Nevertheless, I wanted to share this broke o-ring situation to the brain trust at VansAirForce to encourage everyone not to get in hurry, to listen to your RV and pay attention to the high dollar EFIS avionics we get to put in our planes. Don’t be a NTSB report.
