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Throttle Quadrant Cable Throw

CharlieWaffles

CharlieWaffles

Well Known Member
So to be clear, this question is about the THROW length of the throttle cable, not the overall cable length itself. I just ran a stock vans throttle cable to my stock YIO and the overall length appears ok, but there doesn't seem to be enough through on the quadrant side of things. The stock 2" throw does move the throttle body control through the full motion, but the rod end bearing has to be only about 10 twists on. The throttle quadrant seems to be unable to get full deflection from Open to Close. It seems I have about an inch or inch and half of linear travel on the face of the quadrant I can't use. So I'm think I need a 2.5" or 3" throw to get it to work properly.

Has anyone else done anything like this or do you just live with the partial deflection on the quadrant?
 
Are you saying that the lever on the quadrant will NOT move all the way up/down in it's slot? Or, are you saying the lever moves all the way and you don't get enough actuation at the servo?
 
The throttle quadrant doesn't travel the full length of the quadrant before the servo arm has moved full deflection.
 
I am not sure I understand your dilemma, but I think you are saying that the throw is adequate for the entire servo range, but the cable end is adjusted almost at it's end. You can remove the servo actuator arm and rotate it to adjust the range of travel. It has a geared arm and lever.
I found that I barely had enough throw to go from full idle stop to WOT. Make sure that your idle stop is adjusted to zero when you check the range. It just barely makes it without mod. As Scott has posted, you could modify the quadrant lever by drilling a new hole further out on the arm.

On the same subject. I found that I had to replace the prop gov. arm with a longer arm (made by hartzell) to obtain the proper throw. The short arm that Hartzell provides will limit the quadrant throw to less than half the range available. There is a post on this back in Sept. 2011.
 
The stock 2" throw of the cable is fine for the servo side, I can get full open and idle on it, but I will change the gear arm as you pointed out so I can get the threaded bearing farther onto the cable end.

On the quadrant side of things, the existing attach hole is pretty much at the farthest point on the arm of the throttle lever. A little playing around makes it look like to me that I need to drill a hole CLOSER to the pivot point/farther down the arm to allow the control to move fully from open to close on the quadrant.
 
Yes, if you need more quadrant movement then a hole closer to pivot is needed. Glad I went with vernier controls for ease of installation and inspections.
 
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I dunno. My last one had the stock green cables, quadrant, and the YIO with the Silverhawk. The throttle lever moved stop to stop and just barely moved the servo arm stop to stop.
 
If you drill the hole closer to the pivot point on the quadrant side you will be shortening the travel. If you drill it closer on the the servo side, which you can't do!, you would have more travel. I just barely have the full travel, it took a lot of adjusting to make sure I was able to get WOT.
 
New Hole on servo arm

First of all I have stock length cables and a quadrant. 300 hours on the plane and engine. Everything was working great until I wanted to adjust my idle today by 50 rpm.
I have been doing my conditional inspection this week. I wanted to turn my idle a smidge lower and found out my throttle wasn't actually hitting the idle stop. It was super close but not touching. I noticed the top end was stopping right at the full throttle stop and working good. The problem is when I try to get more on the idle side I lose the top end. I tried a bunch of adjustments until I just drilled another hole on the servo arm. It was super easy and had less play than the factory hole. it worked great and now I have plenty throw on the cable. I can take a pic if anyone is interested.
Hooray for Experimentals!!
 
I may not have been clear

On my first post I meant the servo arm, not the quadrant.
I think almost everyone with a quadrant will have this issue unless the quadrant or servo arm has changed.
I just drilled a new hole like Sean did closer to the pivot point on the arm and it worked perfect.

I know I had a picture and will try to find it.
 
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