mixture cable feels tight in one spot

GeorgeC

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GeorgeC
A few months ago, when pushing in the mixture before start, it traveled freely until it had about an inch to go, and then felt like I had to push it a bit harder to get it through a tight spot, and then the remaining inch of travel felt fine.

I took the opportunity to lube all of the control cables with brayco 363.

It's starting to feel that way again. Why would the tightness be localized? If a low spot on the cable collected water and rusted faster than the rest, wouldn't it feel tight along the whole travel? Vernier mixture.
 
Did you check the linkage? One spot seems more mechanical than excess cable friction.
 
It's starting to feel that way again. Why would the tightness be localized?
Before you get too carried away may want to get some help, disconnect the cable and check the cable separately. Could be a number of things like cable routing slipped or the mixture lever has an issue vs the cable.
 
A few months ago, when pushing in the mixture before start, it traveled freely until it had about an inch to go, and then felt like I had to push it a bit harder to get it through a tight spot, and then the remaining inch of travel felt fine.

I took the opportunity to lube all of the control cables with brayco 363.

It's starting to feel that way again. Why would the tightness be localized? If a low spot on the cable collected water and rusted faster than the rest, wouldn't it feel tight along the whole travel? Vernier mixture.
All good suggestions here. heres another 2 cents, has the cable been in service a long time? (original may be ?) could be a kink, but probably just pushed dirt around over the years, if old, best fix R&R with a new one. Next best is remove it and force lube thru it. The suggestion about disconnect at carb to be sure its the cable and not carb, good idea. I only seen once it was the carb, but that one had car gas left in it for 3 years or so. all the rest stiff / frozen were the control cable issues. By the way if its a "Boden" cable (metal wound, like volks wagon choke cable) sprying lube on the outside may not work, the good ones have an inner sleeve.
 
A few m

It's starting to feel that way again. Why would the tightness be localized? If a low spot on the cable collected water and rusted faster than the rest, wouldn't it feel tight along the whole travel? Vernier mixture.
Cable motion can be complicated since you are trying to force a linear path on an arm that traces an arc as it moves. Changes in function can be due to age, dirt, loosening of a clamp that provides the mechanical ground thereby changing local curvature, something wrong at the other end (carb) or combination of these.

Since this is a new behavior, and was masked/resolved by lubrication temporarily, might want to have an A&P look at it. Most likely it is end of life, but other things may have transpired. Note that if it needs to come out to fix something else, might as well change it unless it's practically new. You want the basic engine controls to work well.
 
My story…

I had the mixture cable bind at times. Cable on its own was fine but carb was the issue. Carb bolts were loose, allowing the carb halves to misalign. I traded it for a rebuilt carb and all is fine using the old cable.

The carb may have bolt anti rotation tabs, but that does not prevent the carb halves from fretting over time.

As others have already mentioned. I would suggest you have the mechanic test the cable and carb linkage separately, and have those carb bolts retorqued if appropriate.

My 2 inflationary-cents worth.
 
I had the mixture cable bind at times. Cable on its own was fine but carb was the issue. Carb bolts were loose, allowing the carb halves to misalign. I traded it for a rebuilt carb and all is fine using the old cable. ...
Lycoming.MSB.0366C.Carb.Throttle.Body.Screw.Loose.r.pdf
 
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