3D Hobby Shop YAK55, Assembly Manual, Page: 26 / 46

Engine Mounting
NOTE: If you are using a canister or tuned-pipe mufflers, you will need to verify the fore-aft location of the
muffler during your engine installation. You may need to temporarily bolt your engine onto the firewall to
check muffler location during that process. For this reason, your sequence of engine/exhaust mounting
may be different from the suggested one.
The Yak can use a variety of 50-70CC single cylinder engines. This manual shows the installation of a
DA60. Other engines are similar. A drilling template is included to locate the mounting holes for the DA50
or DA60 and the DLE 50/55 engines). The Blazing Star 1.5” DA60 machined aluminum mount shown in
the photos is a great match for this aircraft and it provides the proper firewall to prop spacing. Notice that
the firewall on your Yak has right-thrust built in. We do not recommend altering the thrust angle on the
airframe as the right thrust chosen has been carefully selected to provide straight tracking in precision
flight without requiring too much rudder compensation during slow flight.
The correct distance between the firewall mounting surface and the prop mounting surface on the front of
the engine is 6 and ¾” inches. Tape the pattern in-place on the firewall as shown and drill the engine
mounting holes if using one of the lised engines. Included on the pattern is the location for the throttle-
pushrod slot for use with the throttle-servo location in the bottom of the motor box and 50cc engines.
NOTE: Check this location before selecting it for your engine. Some engines' carburetors are reversible
and you can select their orientation.
Begin by drilling the four main bolt holes in the firewall to match your mounting pattern. Then make the
other openings in the firewall for the throttle linkage, choke linkage, and fuel tubing.
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