Up on a soap box....
Bummer. So I took my carb apart and drilled the main jet. I must have messed something up when I reassembled it, because when I started the plane after reassembling everything, the mixture did not work. No leaning, no idle cutoff. I visually verified that the mixture knob was moving the mixture control arm through it's full range of travel, but it was having no effect. So I messed something up internal to the carb.
I've decided it's time to let the pros handle it, and have left the plane with the AME next door.
Any ideas what I might have messed up in my carb that would make the mixture ineffective? Throttle worked fine.
When you rejoined the two halves of the carb, you most likely didn't get the mixture valve engaged on the valve port at the bottom.
This isn't a jab at you personally, but I feel compelled to mention something that I teach in safety seminars I have done.
In the U.S. our E-AB rules are extremely liberal. We can legally repair or maintain
anything on the airplane. The big question is....
should we?
Even though as an A&P, I am certified to work on Certificated aircraft, but I am also required to have type specific training.
Meaning, if Joe Millionair comes knocking on my door and says I am in a hurry, will you quick come change the hydrolic pump on the left engine of my Gulfstream G4 for me? I would have to say no. I have never done that type of work on an aircraft (I have never worked on a corporate jet for that matter). I could gain the type specific training by having another mechanic who is familiar, supervise my work. After that, I would meet the type specific training requirement (for that specific work).
Just because we are home builders, should it be any different?
My opinion is no it should not.
I am not advocating for a change in the rules... I like the level of freedom we have.
What I am suggestion is that if you are about to work on something you have no previous experience with, get someone else involved that does have the knowledge and experience (get your own type specific training).
It worries me on a regular basis, the amount of technical help passed here in the forums, where someone heads off and starts messing around with things that could really get someone hurt (or worse), if the person doing the work, misses an important fact.
No amount of on line help can cover all contingency's. There is still a lot of important details that can fall through the cracks when the people helping aren't actually putting eyes on the project.
In this instance...
I know of engine failures that have occurred because of a messed up mixture valve in a carburetor. You may not know, but because of the way the valve works, it is possible for it to partially function where the valve is only moving through a small portion of its range even though the arm on the carb is moving through its entire range. This can leave you with an engine that runs ok for taxi and run-up, but goes severely lean on climb-out and causes the engine to quit at 200 ft AGL
Ok, off the soap box.....
