DA-85 Throttle Spring....

[Paul Cataldo]

Guys,
Who here uses the DA-85 (or other DA engines) throttle spring as it comes from DA?
Who here is disconnecting the spring to keep the load off the throttle servo?
Should I do this, or leave it be????
I have read of a bunch of guys who somehow disconnect the spring, but they say to LEAVE IT ON, even if you disconnect it???
First off, HOW do you disconnect it? Do you have to CUT the little part which reaches in between the silver and red anodized throttle arms???? I unscrewed the sivler allen head bolt, which holds the red and silver throttle arms together, BUT I cannot figure out how to take them apart, in order to get the springs arm loose????
HOW is this done, and SHOULD I be doing it?????
Thanks.

[lafus maximus]

Hey, I actually just did this the other day on the 85, it is really simple. There is a little hook of the spring that comes through a kind of elliptical hole formed by the throttle arm on the carb and the red aluminum arm bolted to that. all you have to do is push that hook through that hole, that will take the tension out of the spring, but the coil of the spring will stay where it is. I would definitely disconnect that spring so that the throttle servo does not have to fight it. You do not have to cut the spring, just push it through. Let me know if this makes sense, once you push that through the hole, you don't have to do anything else.

[Paul Cataldo]

Yes, I know exactly what you are talking about. I actually tried that, but it was not wanting to push through. Now that I know this is the proper way, I'll make it push through. Thanks.
Oh, BTW, I have no idea why everyone thinks you couldn't just remove the spring entirely. I don't plan on removing it, but I see no reason why it couldn't be removed. It does not APPEAR as if that spring is serving any other purpose, and removing wouldn't really appear to harm anything else....

[JoeAirPort]

Leave it on for safety reasons. On any gas engine I had the spring force was nothing for the servo. The servo is there to provide force, use it.

[krayzc]

mine is left in place....

[Paul Cataldo]

Yeah, maybe I'll just leave it as is. I got caught up thinking it would be better for no tension on the servo, but you guys are right, I will just leave it as is. Thanks guys, for helping me come around.....

[khedge]

I yea I agree I would leave it too. I did release mine but it still has a little tension.

[WOODisGOOD]

You need to leave the spring in place. It acts as a spcacer for the throttle plate. If you remove it the throttle plate will wear on the inside of the carb.

[mikedannielle]

	Quote: Originally Posted by WOODisGOOD
	You need to leave the spring in place. It acts as a spcacer for the throttle plate. If you remove it the throttle plate will wear on the inside of the carb.

Agreed. You can disconnect it, but you have to leave it in as a spacer for the butterfly.

[phippsj]

The spring is there for a very important reason: SAFETY. If your throttle linkage breaks loose or becomes disconnected for whatever reason when the engine is running, the spring is there to close the throttle so the engine just doesn't start doing its own thing.

It's better to dead-stick than to suddenly have a wide-open throttle on a down line or some other position pointing at the ground, people, etc.

If you are worried about load on your throttle servo, then you had better get a decent servo (metal gear, digital). Flying giant scale with a DA-85 requires more than a $15 cheapo servo.

If you still don't believe me, CALL DESERT AIRCRAFT!!!! They design, build, sell and warrant the engine. They should know.

[lafus maximus]

Desert Aircraft states right in the manual for the motor that the spring can be disconnected, but not removed. I have done this on my two 50's and never had a problem. I run fiber optic kill switches on all my gas planes just in case something goes wrong. I am sure it will be just fine if you leave it just how it is, I just found it easier to set up the throttle and everything with the spring disconnected.

[lafus maximus]

This is right out of the manual for the 50, but it is the same for the 85

The throttle arm is tapped for a 2-56 SAE ball link. The spring tension on the DA 50R
carburetor is fairly light and most users will leave it as is. If you wish, the throttle
return spring can be released (not removed) off the end that hooks on the throttle
spring return arm. (Opposite side of the carburetor from the throttle arm)
NOTE: Removing the throttle spring will allow the shaft to move and wear due to
vibration. This wear/damage will allow air and fuel to enter the engine when in the
closed position.