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Mixture Cable Won't Fit?

rockitdoc

Well Known Member
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EXP119 Folks:
I put the mixture cable at midpoint of travel on the panel and moved the mixture lever on the throttle body to midpoint and this is what I get:

Cable Mixture at Cable End.jpg

The heim jointed end is threaded all the way back on the rod end. The cable is adjusted as far aft as it can go, but the cable end is still way far forward of the lever.

Please tell me I installed something upside down. :confused:

Also, my mixture control knob only pulls out about 1/2". Is this right?

Cable Mixture at Max Pull.jpg
 
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What Carl said, plus why are you putting it at the mid point. Put the mixture cable at the full rich, minus 1/6" and then adjust the rod end bearing and clocking the mixture arm that it lines up. Then you should be set.

One thing that I have noticed with the FM200, it takes much less knob turns to rich or lean it. A half a turn of the knob goes a long way compare to my other injection systems.
 
What Carl said, plus why are you putting it at the mid point. Put the mixture cable at the full rich, minus 1/6" and then adjust the rod end bearing and clocking the mixture arm that it lines up. Then you should be set.

One thing that I have noticed with the FM200, it takes much less knob turns to rich or lean it. A half a turn of the knob goes a long way compare to my other injection systems.
^^^^^ Correct answer. All engine controls should be rigged with the arm at it's full open/rich/RPM mechanical stop, and the control knob about one eighth inch from hitting it's stop. This ensures you get what you think you are getting.
And, of course you then check that you are getting the correct result at the opposite end of the control travel.
Also, the mixture cable should be capable of a lot more than a half inch of travel. Typically these cables can have 3 or 4 inches of extension.
 
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What Carl said, plus why are you putting it at the mid point. Put the mixture cable at the full rich, minus 1/6" and then adjust the rod end bearing and clocking the mixture arm that it lines up. Then you should be set.

One thing that I have noticed with the FM200, it takes much less knob turns to rich or lean it. A half a turn of the knob goes a long way compare to my other injection systems.

I just followed the plans instructions. Adjust everything at 50%. Of course this means the fuel is adjusted for the cable limits, not the injector. But, if the adjustment is done at full rich/ full throttle, when the cable is pulled back, it might not achieve zero power or full lean. Am I confused? Wouldnt be a surprise.


The cable only moves 1/2” max
 
Are you talking about the heim jointed bearing at the end of the rod?
If so, I have that threaded all the way back. It’s still too long.

No, not the rod end bearing but the control arm that is part of the servo and held in place with the nut. Loosen the nut and move the arm a bit in the direction that gets you a nice fit and tighten the nut.
In regards to the setup, you want to move the arm to the full rich till it hits the stop, position your control knob at full rich minus 1/6" or so and connect them by adjusting the rod end bearing. Then pull the mixture cable to cut off and watch the servo to make sure it hits the stop at the opposite end.
 
No, not the rod end bearing but the control arm that is part of the servo and held in place with the nut. Loosen the nut and move the arm a bit in the direction that gets you a nice fit and tighten the nut.
In regards to the setup, you want to move the arm to the full rich till it hits the stop, position your control knob at full rich minus 1/6" or so and connect them by adjusting the rod end bearing. Then pull the mixture cable to cut off and watch the servo to make sure it hits the stop at the opposite end.

Gotcha. I got the rod end to fit the servo arm doing this. Worked great. Thanks. I should've thought of that. Duh. Had to move the lever arm one notch/spline.

Full Rich Mixture Cable vs Lever.jpg

Adjustment jam nuts now have four threads showing vs 0 threads before. This is acceptable.

Mixture Adjuster with Four Threads Out.jpg

But, the control knob at the panel does not move enough to get full movement at the servo. I need another 1-13/32" movement to aft for the cable. Not sure why.

Full lean at panel:

Mixture Knob Full Lean.jpg


Full lean at servo:

Mixture Cable vs Servo Lever Positions at Full Lean.jpg


Something's amiss, no?
 

Attachments

  • Mixture Lever at Servo Moved One notch.jpg
    Mixture Lever at Servo Moved One notch.jpg
    259.2 KB · Views: 55
^^^^^ Correct answer. All engine controls should be rigged with the arm at it's full open/rich/RPM mechanical stop, and the control knob about one eighth inch from hitting it's stop. This ensures you get what you think you are getting.
And, of course you then check that you are getting the correct result at the opposite end of the control travel.
Also, the mixture cable should be capable of a lot more than a half inch of travel. Typically these cables can have 3 or 4 inches of extension.


Yeah. That's my experience. But, I have never had this servo and cable combo. My mixture cable needs to move another 1-13/32" aft to get full movement at the servo. But, cable won't pull out that far. Weird.
 
Gotcha. I got the rod end to fit the servo arm doing this. Worked great. Thanks. I should've thought of that. Duh. Had to move the lever arm one notch/spline.

View attachment 33373

Adjustment jam nuts now have four threads showing vs 0 threads before. This is acceptable.

View attachment 33374

But, the control knob at the panel does not move enough to get full movement at the servo. I need another 1-13/32" movement to aft for the cable. Not sure why.

Full lean at panel:

View attachment 33376


Full lean at servo:

View attachment 33375


Something's amiss, no?
I agree, something is amiss. There isn't anything to prevent the cable to move back to its full extension and I assume if you disconnect the rod end bearing, you can pull the mixture out fully, right?

if that is the case,
1- make sure the long bolt you have is not hitting anything to prevent its
movement.
2- If above is confirmed, reconnect and have someone pull the mixture cable and you observe what is stopping it, as there must be a stop to prevent its movement.

If I remember correctly, the mixture arm on on the throttle body is connected in such way that the arm can be moved to the other side of the body. So, check the opposite side to make sure there is no stop or anything on that side.


Sent you a PM
 
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With Your Help the Problem Is SOLVED!

I felt some burrs on the rod at the end of the mixture cable. Filed them smooth and Voila! the cable pulls out of the panel 1-28/32" instead of 1/2" and the lever on the servo is at full aft position, full lean/cutoff.

Full lean at panel, now:

Mixture Knob Full Lean 1-28:32%22.jpg


Lever at servo, now:

Mixture Lever at Servo Full Lean.jpg
 
Thanks Everyone!

You guys are the best. Unflummoxed me, which is easier said than done, sometimes.

:D:D
 
You guys are the best. Unflummoxed me, which is easier said than done, sometimes.

:D:D

Congrats, one more piece completed. Don't forget to tighten the set nut on the rod end bearing with the appropriate size washer on the bolts end.
 
Don't forget to install a large area washer on the bolt thru the arm. This will prevent the cable falling off if the hiem joint fails.
 
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