I am having problems with the throttle linkage binding. I narrowed the problem down to the throttle arm. It goes from the five o'clock position to the nine o'clock position. I am having problems shutting off the engine. The arm just stops at around the seven o'clock position. I think the problem is with the angle of pull on the arm. Would loosening the throttle arm retaining screw and repositioning the arm solve the problem? What do you think? Any help would be appreciated. Thank you in advance.

What type of radio are you using, and is it programmable? Loosening the arm and re-positioning the screw just moves the problem to the other end. Is the throttle opening all the way now without binding? It sounds like the total throw is off and the answer may be in the position of the clevises on both ends. Do you have any ball links, and what hole is the clevis in on the servo and the throttle arm?

few questions before we can give you a good solid answer:

1) does the carb just stop moving? in other words does it seem like the servo tries pulling the carb closed, but it just stops and binds like the carb wont close any further? if so, look on the carb for the idle stop screw. on most engines there is a groove in the carb barrel that rides along the stop screw. the hight of the screw in that groove dictates how far the barrel will turn. loosten it.

2) do you have an ATV (adjustable travel volume) function on your transmitter.. and is it set to decrease throw on your throttle servo? if so, make sure its turned off.

3) are you using a soft throttle cable? check for kinks, bending, or binding. also make sure its not too short or too long.

4) is your servo arm centered on the servo shaft? take off the arm set it so that when the throttle stick, servo, and carb are in the middle position, the servo arm is close to the center of its travel.

You're answering too many posts! You're going to overload the server I thought that maybe the barrel wasn't binding because he said it came back to 5 o'clock normally, but only 7 when hooked up to the radio

maybe one of your replies got sucked into the intake and it jammed his carb open.. ?

for taking the time to help. Now to answer some of your questions.

The throttle barrel is not binding. It will open/close fully. I have a Futaba T6XAS radio, so I was tinkering with the ATV and subtrim functions last night. I also repositioned the throttle arm slightly. It now travels from 8 o'clock to about 4 o'clock. This solved the binding problem.

But, now I found a new problem.
The hole in the throttle arm seems too big for the clevis (standard Sullivan gold clevis). I have to move the throttle trim all the way up just to get the throttle to idle position. Moving the trim to the halfway point just takes up the slack in the throttle arm hole. When I move the throttle stick up and down, the throttle does not end up in the same idle position as set with the trim. I guess I will have to try a ball-link on the throttle arm. I hope it will fit between the throttle arm and the carb body. That's the only place I have room for it. I have between about 1/2" - 3/4" to play with. Do any of you have any ideas on how to tighten up the slack? Any suggestions would be greatly appreciated. Thank you.