User Manual

Hook up the throttle Note: If using a spark ignition engine, be certain to
maintain a minimum distance of 12" [300mm] between electronic parts of the radio system (servo, receiver, battery, etc.) and the engine. Also, never use a full-length, metallic pushrod to operate the throttle. Refer to the following two photos while hooking up the throttle.
❏ 1. If using a U.S. Engines 41cc, move the ball link
ball that was factory-mounted on the bellcrank to the middle hole. Connect a 0-80 ball link ball to the outer hole on the other end of the bellcrank with a drop of threadlocker and a 0-80 nut.
❏ 2. Mark the engine mount where the throttle pushrod
should go through to connect to the bellcrank.
❏ 3. Remove the engine from the engine mount. Bolt
the mount to the firewall without the engine. Being certain not to drill into the fuel tank, drill a 3/16" [4.8mm] hole through the engine mount and the firewall at the mark for the throttle pushrod. Enlarge the hole in the engine mount only with a 1/4" [6.4mm] drill.
❏ 4. Remount the engine to the engine mount. ❏ 5. Cut two 4-3/4" [120mm] forward servo tray
rails from the 1/4" x 1/4" x 12" [6 x 6 x 300mm] hardwood stick. Securely glue the rails to the main side stringer as shown.
Refer to this photo while installing the forward servo tray.
❏ 6. Glue together both plywood forward servo
trays. Place the forward servo tray on the rails. Drill four 1/16" [1.6mm] holes through the servo tray and the rails for the mounting screws. Take out the servo tray and enlarge the holes in the servo tray only with a 3/32" [2.4mm] drill. Mount the tray to the rails with four #2 x 1/2" [13mm] screws.
❏ 7. Cut the 3/16" x 24" [4.8 x 610mm] gray pushrod
guide tube to the correct length for the throttle. Use coarse sandpaper to roughen the tube so glue will adhere where it goes through the firewall and formers. Slide the guide tube into position.
❏ 8. Fit the throttle servo in the servo tray. Cut the
white, plastic pushrod to the correct length so it can be connected to the throttle servo with a nylon clevis and to the bellcrank with a nylon ball link.
❏ 9. Thread a 2-56 x 1" [25mm] threaded rod into
both ends of the throttle pushrod. Connect the nylon ball link to one end of the rod, then slide the rod into the guide tube from the front.
❏ 10. Connect the nylon clevis to the threaded rod
on other end of the pushrod. Connect the clevis to the throttle servo arm with a silicone retainer. Use medium CA to glue the guide tube to the firewall and the formers.
❏ 11. Remove the forward servo tray. Add a few
drops of thin CA to the holes in the servo tray rails and allow to harden. Mount the throttle servo to the tray as well. Remount the servo tray.
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