Throttle

[wadeg]

Back to the throttle tugging question.
Been taxiing the fox. If I let go of the throttle, it lurches to about 3000 rpm. What are you all doing to fix it? What springs are ideal for a replacement? To avoid it from happening, I have to really tighten down my throttle lock. Seems hazardous to me.
Thanks!
Wade

[84KF]

Wade,
I took mine off and now it stays where you leave it. Pull it back to 1500 and it stays there. Same withe 1800, 2000, 2200...etc.

If you have "cables" instead of "wires", give it a try. Just take them off. Cables arn't gonna break (and will be inspected on a regular basis). And lubricate the throttle housing at the panel.

It will make a big difference.

[Skybolt]

Wade.
I agree. the return to full throttle spring is on the strong side.

But Steve, should the springs be in place, in case there is a cable break or slip?
Maybe to replace the OEM springs with a lesser spring would be a better alternative than removing the springs.

Maybe, we can throw this out, anyone changed to a weaker set of springs on the 912?

Eric.

[wadeg]

Well I went by ACE and got a few different springs to try. Used a lighter spring that has the same length as the standard and looped ends. Works perfectly now. Silky smooth and not hopping off idle. Can't recall the specific spring number but ACE usually has a rack displaying them all up on a pegboard in the nut/bolt section. Problem solved!

[Skybolt]

Wade.

Thanks for the feedback.

I assume you have the 912 motor?
What did you do, remove one of the springs (for a pattern) and pick the closest to it in length/shape?

Cheers. Eric.

[wadeg]

I'll have to drop back into ACE and see which one I got. I bought a few of them that were in the range since they were inexpensive. I got to the hangar, opened em all up and when I went back to check which ones I selected for use, I forgot which bag they came from. Will drop into ACE and see which one I specifically am using and post the number. Also will need to keep a close eye on them for any evidence of wear. The tension is perfect. It is just enough to keep from pulling the throttle forward when at idle (running with vibration). With a little bump it will ease forward but stays in position. No doubt it will toss the throttles to full should the cable break. Happy with my throttle now after plenty of agst.
Just about done! Only thing really on my 'list' for completion is to get my data plate on. Then I will start thinking of more things to do.....

[Jerrytex]

I found this post in a search. My test pilot flew my Kitfox for the first time ever (yeah!) this past Sunday. I have the Rotax 912 with the dual throttle cable and the friction nut to hold it. He mentioned that he felt the throttle creep was a bit of a safety issue. We talked about it neither one of us can think of a reason that there needs to be return springs. I get and understand the going to wide open throttle theory if the cable breaks but this would only be a real concern on take off and highly unlikely if checked on a regular basis.

I took my return springs off and the throttle works like the Aeronca Champ that I have been flying. It stays were you put it with no creep and no cranking down on the friction nut.

Is there anyone that has had problems from removing the springs? Or the ones that have, any unforseen issues that you have experienced?

Thanks

[DesertFox4]

780 hours now without the springs in place. No problems. I have Kitfox Aircraft LLC's heavy throttle cable with the friction lock.
You should consider all possibilities before removing them and do what you feel is reasonable and prudent.

[Slyfox]

seems I hated that on my new 912uls. I opted I believe, to just remove the springs off my old 912ul engine, that fixed mine, works fine. the springs on the old motor were much lighter on springs.

[MotReklaw]

A friend of mine changed the return springs on his 912U.
Here's a link to what happened to him.

I'm just saying....

http://www.ch601.org/stories/croke_crash.htm