Leaning a Mooney

[Paul Allen]

I have a 1981 M20J/201 and my home airport is 1228'.
Should I lean the engine for warm up and taxing? I have
only been leaning after I get up to cruise altitude.
Thanks

 

[Mark S]

I have a 1981 M20J/201 and my home airport is 1228'.
Should I lean the engine for warm up and taxing? I have
only been leaning after I get up to cruise altitude.
Thanks

By leaning on the ground you will eliminate many of the issues with lead fouling of your plugs. I lean aggressively on the ground until I do my run up, then go full rich for takeoff. You will not damage your engine by doing this.

Mark

 

[Paul Allen]

Mark,
Thanks for the reply. How long after starting the engine before you lean the engine? Is there any concern for engine damage when it's cold out? (Ohio weather)
Thanks

 

[Greebo]

Not specifically mooney related, but I lean after we start taxiing and we're "maintianing" the ground speed.

 

[Ken Ibold]

Mark,
Thanks for the reply. How long after starting the engine before you lean the engine? Is there any concern for engine damage when it's cold out? (Ohio weather)
Thanks

I ground-lean as soon as the engine is running smoothly. The power settings are low enough that you're not going to hurt it. In fact, the leaner mixture will help the engine run better. At taxi power settings, lean as much as possible. If you go too far the worst that can happen is that the engine will stop. An added benefit of leaning A LOT rather than a little on the ground is that if you forget to advance mixture before takeoff, you won't generate enough power to accelerate for takeoff.

 

[Carol]

By leaning on the ground you will eliminate many of the issues with lead fouling of your plugs. I lean aggressively on the ground until I do my run up, then go full rich for takeoff. You will not damage your engine by doing this.

Mark

I do the same for the Comanche. If I do not I spend time in the runup area before take off clearing the plugs.

Carol

 

[Greebo]

With regard to leaning on the ground...

...if you're at a small airport, one place NOT to practice leaning on the ground the first time is when back-taxiing on the runway.

I did as a student pilot, and the engine quit on me while I was blocking the runway.

 

[RobertGerace]

With regard to leaning on the ground...

...if you're at a small airport, ...and the engine quit on me...

Me too -- but not on the runway. I was on the ramp and the line-guy was standing there, and I grabbed the levers and just pulled them back about 1/2 way and they both quit! I think I turned as red as the handles before I could get them started again...

 

[Paul Allen]

Thanks for all the responses. I guess I better start leaning on the ground.
Paul

 

[glpilot]

Several of the instructors I have had taught me to lean on the ground. I actually had a hard time knowing how much to lean when inflight. I think I have gotten a better feel for leaning the mixture now. I had to become more aware of the leaning mixture process because I thought it was important enough. Now I feel the same way when I taxi. Try to keep things from going foul.

I have to admit at times when in flight, I'm putting the coals to it in the 172R, and I just want to get to my location thats only 30 or so minutes away, I have run it pretty rich if not full rich just trying to get there quickly. I try not to get into that habit.

I think I just need to learn to fly a faster plane.

 

[Len Lanetti]

I actually had a hard time knowing how much to lean when inflight. I think I have gotten a better feel for leaning the mixture now.

Without one of the fancy engine monitors I lean until it gets a little rough then enrichen a tad.

With the older engine monitor that is in the Mooney I lean until it gets a little rough, enrichen a tad and then I watch the engine monitor.

On the old engine I had one cylinder that would run at close to 400F unless I enrichened a little more.

Len

 

[gismo]

One thing you'll find when leaning at or near idle is that the effect of moving the mixture control is much slower than it is at cruise power settings. For that reason, if the engine begins to miss or the RPM drops, the best way to insure it doesn't quit completely is to note the position of the mixture and ram it back to full rich. Leave it there for several seconds and then pull the mixture back to a point not quite so lean as the last time.

And you shouldn't be leaning on any runway. Pull off onto a taxiway first.