The fuel servo installation has been fun. I ended up doing a fair amount of research, and even bought “Aircraft Fuel Metering Systems” from Aircraft Technical Books to make sure I knew what was going on here. Here’s a nice drawing I found. From the schematic you can see that the manual mixture control arm is nearest the fuel inlet, and the throttle is near the safetied end nut of the fuel strainer. Thus in the figure below, the throttle has the idle mixture adjustments. The mounting brackets for the control cables are the standard kit from Velocity, but it was a little unclear whether it should go under the servo flange or not. So, concerned that I wouldn’t get a good seal that way (see picture below), I decided to mount it on the bottom side.

Fuel Servo

Here is another drawing, a schematic showing how these things work, and here’s a troubleshooting guide for the servo. We’ve installed dual throttles, so here you can see them converging on the throttle side of the RSA fuel servo – the mixture is on the co-pilot side.

Servo Schematic

Servo Troubleshooting

Throttles Converge on Pilot Side

Mixture Cable

Throttle Cable

Mixture Control

Fuel Servo from Rear

Servo Control Mounting Brackets


Posted By: Brett Ferrell
Sunday May 1st, 2005 at 7:48 PM

Categories: Engine Plumbing
Tags: Building Engine Fuel Injection Fuel System Fuselage

One response to “Mounting the Fuel Servo”

  1. Document says:

    […] “80% done, 80% to go stage”. The completed exhaust has been installed, and the fuel servo was mounted and ducted along with the oil cooler. The last of the engine (EGT, fuel and oil […]

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