I just started building a SIG 1/5 scale J3 Cub kit, the instructions tell you to install the motor mounts to the firewall then install the motor on the mounts,I am using a Magnum XL 52 4 stroke mounted on its side. After installing the motor the correct distance from the firewall, the throttle arm is only 1/4" away from the firewall at full throttle and 3/4" away when fully closed. SIG supplies a flexible steel cable and a nylon tube for the cable to go through. I don't think there is enough room to use this type of set up. What would be the best way to set this up? any help would be appreciated

Dubro makes a bellcrank setup that bolts to the engine mount
http://www2.towerhobbies.com/cgi-bin...?&I=LXD939&P=0

Page 24 has a picture of it installed
http://dubro.com/DUBRO2005CATALOG/index.htm

Another way to do this is to use a 2-56 rod from the throttle arm to the servo. Solder a clevis to one end, and bend the rod back on itself in a small half loop (the end with the clevis). Slide the rod through the tube and connect the clevis to the throttle arm (it will come in from the front of the arm), and use a quick link from the rod to the servo arm. You might not be able to use as sharp a bend in the guide tube as you would with the flex cable. The bellcrank idea is good, too, you can drill and tap the engine mount arm to mount the bellcrank to align it with the throttle arm. Both methods just redirect the direction the control rod connects to the throttle arm.

Use the flex cable and an EZ-Connector on the throttle arm. Works great.

Dr.1

Had the same situation with a couple of my scratch builds. I just lined the pushrod up with a screw lock connector, and the cable works fine. Just need to take time to get it aligned and it will give you no trouble.

I went through a lot of trouble mounting the throttle pushrod on my OS 70FS (in a Goldberg Tiger2). I recessed a small box to give me enough flex room with a plastic weedeater wire. It works well, but soon after that I saw an illustration of a simple U-bend in a 2-56 pushrod. Run it long enough to go past the throttle arm on the engine then just bend it 180 degrees. Gives plenty of flex room and is easy to execute.

==Mike==

I run the narrowest tubing that I can find all the way to the firewall. I use very thin piano wire. I can't remember the diameter, maybe .030. It doesn't need much strength. I put z bends at the throttle arm on the carb and at the servo. Very light weight, easy to maintain, and works well.