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  #1  
Old 12-04-2017, 03:14 PM
Geeman Geeman is offline
 
Join Date: Apr 2010
Location: Houston TX KDWH
Posts: 389
Default Help with slight loss of engine power/running rich

I have an RV-6, O-360, 850 hours, built it 2000.

On take off and climb out the other day it felt a bit low on power. As I was climbing I started leaning it a little and the power came up. It felt like I was at a high altitude airport or like the carb heat was on. It has not normally required leaning like this before. I am basically as seal level and 70-80 degrees. Something seems to have changed. I checked to make sure the carb heat door is fully closed and it is. I checked the idle mixture (which understand does not really effect full throttle) and I got a 20-30 rpm rise right before shutoff idling at 1000 rpm.

This is the original carb and I have not touched it since I purchased the plane. Been running fine. Is it time for a carb overhaul? Could the float be causing a problem. I know very little about the internals of the carb but I can always learn.

Any suggestions on where to start troubleshooting?
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Purchased and sold flying RV-6
RV-7 Kit (sold to purchase C150 to train my kids)
Purchased flying RV-7
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  #2  
Old 12-04-2017, 03:15 PM
Geeman Geeman is offline
 
Join Date: Apr 2010
Location: Houston TX KDWH
Posts: 389
Default Carb shop in Houston?

If the carb needs overhauled, could someone recommend a shop in the Houston area.
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Purchased and sold flying RV-6
RV-7 Kit (sold to purchase C150 to train my kids)
Purchased flying RV-7
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  #3  
Old 12-04-2017, 03:49 PM
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Raymo Raymo is offline
 
Join Date: Nov 2014
Location: Richmond Hill, GA (KLHW)
Posts: 2,340
Default

At 17 years, I'd suggest it is time to OH the carb but would not rule out some other components that are involved, like mags, wires and plugs.

Take-off power at sea level is typically full rich. You can lean it a bit any day and produce more power but at the risk of detonation (some say it is not a concern). Many old A/C POH's promoted this method for take-off (max power) but it is not generally recommended these days unless you are taking off at a sufficiently high DA where you cannot make more than 75% power.
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RV-7A - Slider - N495KL - First flt 27 Jan 17
O-360-A4M w/ AFP FM-150 FI, Dual PMags, Vetterman Trombone Exh, SkyTech starter, BandC Alt (PP failed after 226 hrs)
Catto 3 blade NLE, FlightLines Interior, James cowl, plenum & intake, Anti-Splat -14 seat mod and nose gear support
All lines by TSFlightLines (aka Hoser)
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  #4  
Old 12-04-2017, 11:24 PM
F1R F1R is offline
 
Join Date: Nov 2010
Location: ____
Posts: 911
Default

Do the wiggle test with the bottom half of the Marvel Dribbler. Normal engine vibration will loosen the threads and allow for a loose bowl/lower body.

Also agree with the mags being possible suspects if they are past 800 hours.
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  #5  
Old 12-06-2017, 02:55 PM
spitedge spitedge is offline
 
Join Date: Dec 2010
Location: Sydney Australia
Posts: 7
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I had the same issue with the rv4 (0320 160hp c/s). Basically the engine was running to rich at sea level with lower EGT's and associated reduced power at take off which was noticeabley worse on hot days. Replaced the jet inside the carb with a new one and problem solved. EGT's went back up the around 1430 on take off and power returned also, havent had any further issues in the oast 12 months. Cant explain how the jet size would change over time but it definitely fixed the issue

Cheers
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