I am builing a 40 size Funtana ARF and I have a Magnum 80 4 stroke on it. The carb. is only about 3/8" from the firewall which doesn't seem to give me enough room for the throttle arm linkage. Any suggestions?

You sound like you might need a 4 cycle style linkage for your throttle. You need to have your pushrod extend out past your carberator and then bend a 180 turn in the rod to go back to the throtle arm on the carberator. This is quite common for 4 cycle engines. Hope this helps and Good Luck, Dave

I often do it like DaveAgar does, sometimes I need to provide a guide out near the backplate of the spinner to keep the longer pushrod from having excess movement under vibration. Mount the guide under one of the motor mounting bolts.

Like Dave said, run the pushrod out then do a 180 degree bend back to the throttle arm.
Dennis-

Hi
The other thing you can do is put an 90% bracket on your actual engine mount further forward so as it can swivell then you can link from carb to bracket then back to servo

Hope this can be understood
ROB

A 4 stroke throttle linkage is available but I made mine. My project with pictures is at:

http://www.rcuniverse.com/forum/My_M...2005916/tm.htm

Good luck!