RCGF 20cc SBM - Page 8

engine.
Note: Please remember to remove the prop washer(S2024) and the small blind nut,
when you mount the adapter nut in your 20cc SBM engine.
1. Select an engine mount. A two-piece engine mount that does not interconnect or
overlap at the firewall is preferred for the RCGF 20cc SBM
2. Before securing the engine mount to the firewall, test fit the engine onto the mount and
place the mount onto the firewall. Press the blind nuts into the rear of the firewall. If you
choose to use regular nuts or lock nuts be sure to place washers on the bolts before
securing the nuts onto the bolts on the rear of the firewall. Be sure to use Threadlocker
on the screws holding the engine mount to the firewall.
3. Place the engine on the engine mount and at the recommended distance from the
firewall and test-fit the cowling on the aircraft to verify the distance. When you’re satisfied
with the engine’s position, mark the location of the four holes on the mount.
4. Remove the engine from the mount. Drill and tap the engine mount at the position of
the four mounting holes. Use an appropriate size
screw. It’s a good idea to drill and tap all the way through the mounting beams in order to
secure each screw with a lock nut.
5. Secure the four screws with lock washers, flat washers, and lock nuts.
6. Install the fuel tank in the airframe. Use only gasoline-safe fuel lines and a gasoline
safe stopper. One line should go to the carburetor and the other is to be used as a vent
(a vent line is simply an open ended fuel line from the fuel tank which exits the engine
compartment or the fuselage; most vent lines exit at the bottom of the firewall).You can fill
the tank by using the carburetor line as fill line if you have access to it or install a third
line to be used as fill line. Installing a third line is the cleanest and easiest way to add fuel.
An alternative fueling set up is a 2-line system with a T-fitting approved for gasoline use.
Be sure to use a filler plug with either a 2 line or 3 line set-up.
It is a good idea to add an extension to the vent line as shown, that goes up and to the
rear of the tank. This helps to avoid draining fuel from the tank when the model is pointed
down.