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 FerrellSunday May 1st, 2005 at 7:48 PM
Categories: Engine Plumbing Tags: Building Engine Fuel Injection Fuel System Fuselage
[…] “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 […]