OHIO MODEL Products 120CC Yak SP-55M User Manual - page 12
the rudder centered, adjust the cable length as tight as possible while checking the ball link position over
the servo arm. When satisfied with the position, pinch the cable around the threaded coupler and then
feed the loose end back through the brass tube. Loop the cable back through the brass tube as before and
crimp the brass tube three times just tight enough not to cut the brass tube but enough to securely hold the
wire in place. Cut off the excess cable with wire cutters. Wick thin CA into the brass tube to help hold
the cable secure. Repeat for the other cable. Hint: Once you have established the position of the
threaded coupler on the cable, you can remove the ball link from the rudder horn to give you more
working slack in the fuselage. Re-install the ball link prior to setting the other cable.
7. Check the operation of the rudder using your radio and make sure there is no binding and the cables
are adjusted properly. You may have to tighten the cables after a few flights as they may stretch slightly
from the initial installation.
ENGINE, EXHAUST, & FUEL SYSTEM INSTALLATION:
1. Templates are provided in the kit for both DA and 3W 100 cc engines as well as the DA 120 engine.
Select the proper guide for your engine and mark and drill the mounting holes and cut out the center as
indicated. Notice that the engine center line is offset to the left to compensate for the right thrust built
into the engine box.
2. Place the cowling in place on the fuselage and measure the distance from the firewall to about 1/2” in
front of the cowling. This figure represents the back of the spinner and will help you determine if you
need to space your engine out from the firewall using washers or additional wood. Mount your engine
securely using bolts, washers, and locknuts. The use of thread-lock is also highly recommended for the
engine bolts.
3. Mount the ignition module according to the manufacturer’s instructions. The best place to mount it is
on the side or top of the engine box. Secure the pickup lead and ignition wires with zip ties so that they
do not vibrate or touch any hot part of the engine or exhaust. The picture below shows the DA100 engine
installation. The author prefers to protect the ignition wires with cable wrap to prevent wear of the mesh
shielding.