Hi,
I am setting up the throttle connection on my DLE 111. I am planning on disconnecting the throttle return spring on the carb so there is not the constant tension on the throttle servo. Is this a good idea? Is this common practice ? any down side? This is my first 111cc airplane so any advice would be appreciated.
Thanks,
Jim

Yes that is a common practice,
Unhook the spring but DO NOT REMOVE IT.

On some carbs you can hook the spring into a lessor hole so the spring tension is not so great.

I use to disconnect the springs or move the hook to a hole with less tension, but for the last several engines, I just leave it in place. If you measure the current drawn by the throttle servo with the spring in place, the draw is minimal. It takes very little servo power to overcome the spring. There is some safety in leaving the spring in place. If the throttle linkage should fail for any reason, the throttle would spring closed.

+1

I leave the throttle springs connected untouched nowadays. The small amount of poad on the servo does no harm at all. In fact the benefits are very high - such as
- The throttle returning in the event of a linkage failure.
- The preload given by the spring actually reduces the chance of a throttle linkage failure by keeping the wear, caused by engine vibration, on the linkage parts (Including the servo gears) down.

The minus? - the flight pack battery won't last as long but that is so minimal that it won't affect the number of flights you get between charges.

Ditto!

No removal. The tension will force the throttle back to idle when the linkage breaks. A rare possibility but the tension helps here.

A very good reason to leave the spring on!
I'll add one more. With the throttle linkage/servo counteracting the small load of the spring, the throttle shaft and butterfly not being able to vibrate freely, as the spring will take up any play in the linkage. I've been told this will result in reduced wear between the throttle shaft and carb body, makes sense to me.
Pete

Man I love this thread. I always wondered why people insisted on disconnecting the spring tension. I leave it as-is for reasons mentioned by smart people in this thread. It uses practically no current. If it's a really tight spring I might relieve a little tension like W8ye said (I seem to always agree with you W8ye).

w8ye is a wise man, following his advicealso shows wisdom.

Leave the spring alone as it is from the factory, hopefully you'll never learn first hand the reasoning behind the wisdom. It's covered pretty well by others in this thread.</p>

Well due to the school of hard knocks, back 15 yrs ago or so I ruined a stock carb on a weedie conversion by completely removing the spring.

Removing the staked screws from the plate on that carb to get the shaft out was not a good idea as you cannot get the screws back like factory had them fastened.

You can reposition the throttle plate back in the correct position and LocTite the screws but . . . .

The spring acts as a tension type locator for the throttle shaft and without the spring, the throttle plate locates the shaft. The edges of the plate drag on the throttle bore and causes additional friction, more so than what the spring does. Needless to say, after figuring this out, the carb went into the junk box.

Leaving the spring on the carb, some people were cutting the tang end from the spring but you can never hook the spring back onto the arm.

As said by others, on most carbs, a standard 40 oz servo will overcome the spring tension just fine and the spring tension keeps all the slack out of your throttle linkage providing better control and reducing wear.

Well,
After reading this post I think I will leave the spring in tact. Thanks to all who responded.
Jim