I've just recieved a new Taurus TS-72 gas engine. The spring that returns the throttle to idle is very stiff and will make the throttle servo work hard at any setting above idle. I assume the main reason for this spring is safety. Do most of you leave this spring on, or cut it out. Thanks for any input.

If you want to eliminate the return spring force do NOT cut it out! They are required to keep the butterfly in the correct place. Just unhook the little hooked portion (so the spring is still there but not "hooked up") or trim the hooked end off. The spring will then still press outwards but not provide any return force.

Andrew Coholic

The spring is for a chain saw throttle. Are nice for test stands but i remove them for a/c installation.

Some engine manufactures void the warranty if you remove the return spring. I think I would read the manual that came with your engine. Like Andrew stated above, They are there for 2 reasons. 1. To return the throttle to its idle position. 2. To keep the butterfly in the proper location for smooth operation. Just cutting the hook off will do the trick. Just my 2 cents.

rbeck

Rbeck - thats correct! All the brisons I have owned (3.2, 4.2 and 6.4) have stated in the manual NOT to remove the spring. Voids the warrenty indeed!

Andrew

The walbro website makes no mention of R/C engines. Spring can sure make for a less than smooth throttle, complete with binding and less than reliable operation.

I personally leave the spring intact on all my gas engines. I figure if the throttle servo ever fails it will go to idle and possibly save the plane.

I use a GOOD throttle servo (like a JR8101 or hitec dual BB coreless) that has power. If your throttle linkage is smooth and free, I cant see how the spring will make anything "bind" or cause trouble?? In a chainsaw, weedwacker or any other device in which the spring is there to return the throttle cable to idle position, it obviously functions smoothly. Therefore the spring alone shouldnt contribute to any "binding"! On the contrary, if the spring is removed on certain models of carb, the butterfly can move out of position slightly, and jam up (know this from trying it myself) THEN you will have binding!

So, follow the manufacturers recomendations, leave the poor spring intact and if the small bit of return force really bothers you just nip the hooked end with a pair of side cutters and thats that. Trust me!

AJC

Leave it on, just disconnect the loop from the throttle arm if you feel its too stiff.

How does the spring interfere with the throttle?