OK,
I need your help one more time. I installed one of them plastic pushrods, the one with a plastic sleeve on the ouside, and plastic thinner rod on the inside. I glued and drilled into my smooth piper cub firewall a plastic sleeve, installed the engine, and throttle servo, then to MY COMPLETE HORROR the rod and the throttle arm are not lined up! The pushrod comes out of the F/wall at about 1/4 inch away. My question is: Is there a throttle linkage thing to help resolve this problem? Should I get a wire pushrod? Any comments always appreciated. Thank ou.

POCHO,
Depending if you are 1/4 inch off high/low, or left/right of the throttle arm, you can probably get away with using a ball link on the throttle arm and nyrod link.

Should this not work, try putting a "Z" bend in the nyrod's metal threaded pushrod. The size, and direction, of the "Z" bend will be determined by offset of pushrod and throttle arm.

Either method should work. A 1/4 inch is not that bad.

Could you add a short length of 2-56 wire to the end of the plastic rod and bend it enough to reach the throttle? I have a "situation" with an OS FS-70 II that has a rear carb and the throttle arm almost touches the engine mount. I plan on running the pushrod through the firewall above the mount and using an "L" bend in the wire end to reach the throttle arm.

Yeah Im about 1/4 inch to the left of the the throttle arm. Thes are both great ideas. I will try both to see which will work out best, thank you. (My first scale project has become somewhat of a nuisance)

No Problem!

Another way which works well and will accomodate a much greater missalignment is to just run the pushrod out past the throttle connection, bend a U turn in the wire and come back to the throttle all lined up. This does require that you have a metal end long enough for the bend to be threaded into the nyrod at its exit of the firewall. This works very well with 4 strokes where you have to clear the fuel tank with the control rod yet get back to the throttle positioned inboard and very near the firewall.

Yea, I've done it Rodneys way too. That works well.

I defer to Rodney's idea. I just did some office-supply empherical testing (bending large paper clips) and the "U" has is much less slop than an "L" or "Z" with the same offset, though I can't determine "Y". . . I mean why.