New owner, new to Mooneys (M20F)

[iamit]

Just wanted to say hi to what looks like an amazing community - makes me feel like I made the right choice with the M20F as my first plan I own (after flying mostly in 172s and a bit of PA32).

Picked up N9363V yesterday for a long cross-country from Lexington to Farmingdale (almost all of it in IFR-IMC) which was a great boost to my instrument rating training, and I'm 100% in love with the aircraft ;-)

Quick question though - at cruise, when trying to pull back on the throttle to reduce manifold pressure it seems like either it takes a lot of "travel" to get movement on the MP, or that the MP is reacting in quite a delay to throttle inputs that aren't major (more than 1/4 of the travel for the handle). Am I missing anything here? Maybe some loose cables?

[gwav8or]

Welcome aboard! I picked up my F about 6 weeks ago. These are amazing little birds for sure!

Idk about the manifold pressure issue, but you’ll get a lot of good info from the awesome folks on this forum.

You also have Don Maxwell in East Texas (I believe), who’s is THE Mooney guru.

Best of luck and CAVU!


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[KLRDMD]

23 minutes ago, iamit said:

Quick question though - at cruise, when trying to pull back on the throttle to reduce manifold pressure it seems like either it takes a lot of "travel" to get movement on the MP, or that the MP is reacting in quite a delay to throttle inputs that aren't major (more than 1/4 of the travel for the handle). Am I missing anything here? Maybe some loose cables?

Why would you pull back the MP at cruise (unless you're really, really low)? In a normally aspirated Mooney, the throttle goes fully in for takeoff and you start to back it off when you need to slow to gear speed when setting up to land. It sounds like it may be a good idea to get a Mooney specific CFI to do your tranistion training. Just any old (young) CFI from your flight schol won't be doing you a service.

[Ragsf15e]

35 minutes ago, iamit said:

Just wanted to say hi to what looks like an amazing community - makes me feel like I made the right choice with the M20F as my first plan I own (after flying mostly in 172s and a bit of PA32).

Picked up N9363V yesterday for a long cross-country from Lexington to Farmingdale (almost all of it in IFR-IMC) which was a great boost to my instrument rating training, and I'm 100% in love with the aircraft ;-)

Quick question though - at cruise, when trying to pull back on the throttle to reduce manifold pressure it seems like either it takes a lot of "travel" to get movement on the MP, or that the MP is reacting in quite a delay to throttle inputs that aren't major (more than 1/4 of the travel for the handle). Am I missing anything here? Maybe some loose cables?

Welcome!  They are great planes!  
The throttle should give immediate response.  Maybe you need a slight adjustment in the travel?

As @KLRDMD said though, you’ll eventually learn to just leave full throttle from takeoff through cruise and most of your descent.  Unless you’re flying relatively low, like below 5k.  For engine longevity, you’ll probably want to cruise at 75% power or less.  You can check the poh for this, but in a normally aspirated aircraft, flying above about 5k usually takes care of that.  There are “key numbers” that also are a guide for 75% power. 
 

For cruise, You will reduce rpm (2500 is common) and lean for cruise, but leave full throttle.  

Learn how to fly lean of peak which is pretty easy in a lot of io-360s.  Do you have an engine monitor?

Post some pictures when you have a chance.  They are great airplanes!

[N201MKTurbo]

1 hour ago, iamit said:

Just wanted to say hi to what looks like an amazing community - makes me feel like I made the right choice with the M20F as my first plan I own (after flying mostly in 172s and a bit of PA32).

Picked up N9363V yesterday for a long cross-country from Lexington to Farmingdale (almost all of it in IFR-IMC) which was a great boost to my instrument rating training, and I'm 100% in love with the aircraft ;-)

Quick question though - at cruise, when trying to pull back on the throttle to reduce manifold pressure it seems like either it takes a lot of "travel" to get movement on the MP, or that the MP is reacting in quite a delay to throttle inputs that aren't major (more than 1/4 of the travel for the handle). Am I missing anything here? Maybe some loose cables?

Do you hear and feel the power reduction before it indicates? If that is true you should clean the restrictor in the manifold line or the restrictor in the gauge inlet. If you don't feel the reduction and the power seems to follow the gauge, take off the right side lower cowl cover and check for slop in the throttle linkage.

Be sure to check the security of the cable conduit clamps under the engine. They will often get loose allowing the cable housing to slip in its clamps. This will allow the cable response you describe.

If you are new to airplane maintenance, get a mechanic to help you. 

[Shadrach]

28 minutes ago, KLRDMD said:

Why would you pull back the MP at cruise (unless you're really, really low)? In a normally aspirated Mooney, the throttle goes fully in for takeoff and you start to back it off when you need to slow to gear speed when setting up to land. It sounds like it may be a good idea to get a Mooney specific CFI to do your tranistion training. Just any old (young) CFI from your flight schol won't be doing you a service.

Like a good owner that wants to learn about his bird, he has likely been reading his owners manual!  The manual suggests a power reduction to 2600X26" for climbing. It suggests reducing MP to desired book power settings in cruise.

@iamit, N9363V is a nice looking bird.  There are more optimal ways to operate (as Ken @KLRDMD alludes).  You're in the right place.

Rich @N201MKTurbo has covered the things you can investigate. The goal is to determine if it is an indicator issue or an actual lag in throttle response.

[KLRDMD]

2 minutes ago, Shadrach said:

Like a good owner that wants to learn about his bird, he has likely been reading his owners manual!  The manual suggests a power reduction to 2600X26" for climbing. It suggests reducing MP to desired book power settings in cruise.

Which is exactly why he needs a Mooney specific CFI to transition him into this airplane. Such a CFI would know what parts of the owner’s manual are worth following and which ones have been proven inaccurate in the 60 years since it was was published.

[Shadrach]

1 minute ago, KLRDMD said:

Which is exactly why he needs a Mooney specific CFI to transition him into this airplane. Such a CFI would know what parts of the owner’s manual are worth following and which ones have been proven inaccurate in the 60 years since it was was published.

I agree. I was just pointing out that his operations are not outlandish but recommended. He needs to find the right Mooney CFI. Just because this place is full of POH heretics (guilty), does not mean that it's common at the local drome.

[N201MKTurbo]

The OP asked about a throttle response issue, not about how to fly his plane.

Maybe he was trying to prove that a Mooney really does use less fuel going 120 KTS than a 172 or Cherokee.

[iamit]

Wow, this is exactly what I was looking for here!
And yes - I was following the POH and trying to match the mp/rpm at different altitudes, but mostly what it was about was descents… I’ve been used to pull on the throttle to start a descent and just let the plane pitch down and establish a descent rate while adjusting power/pitch. My CFI let me play with that but told me that in these planes you mostly pitch for descent while controlling airspeed to not exceed the standards.
And you are all 100% right - below 4-5k the throttle response was much more linear and controlled as I was practicing the approaches and landings.
Was mostly curious about that throttle response up higher which makes sense since it matches the poh power combinations when pretty much at full open.


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[iamit]

Do you hear and feel the power reduction before it indicates? If that is true you should clean the restrictor in the manifold line or the restrictor in the gauge inlet. If you don't feel the reduction and the power seems to follow the gauge, take off the right side lower cowl cover and check for slop in the throttle linkage.
Be sure to check the security of the cable conduit clamps under the engine. They will often get loose allowing the cable housing to slip in its clamps. This will allow the cable response you describe.
If you are new to airplane maintenance, get a mechanic to help you. 

I don’t really feel much power difference and when I do it is indicated in the MP. But I was doing those at above 8k so it probably makes sense (and while ram air was open).


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[iamit]

Welcome!  They are great planes!  
The throttle should give immediate response.  Maybe you need a slight adjustment in the travel?
As [mention=7117]KLRDMD[/mention] said though, you’ll eventually learn to just leave full throttle from takeoff through cruise and most of your descent.  Unless you’re flying relatively low, like below 5k.  For engine longevity, you’ll probably want to cruise at 75% power or less.  You can check the poh for this, but in a normally aspirated aircraft, flying above about 5k usually takes care of that.  There are “key numbers” that also are a guide for 75% power. 
 
For cruise, You will reduce rpm (2500 is common) and lean for cruise, but leave full throttle.  
Learn how to fly lean of peak which is pretty easy in a lot of io-360s.  Do you have an engine monitor?
Post some pictures when you have a chance.  They are great airplanes!

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[Shadrach]

37 minutes ago, iamit said:

Wow, this is exactly what I was looking for here!
And yes - I was following the POH and trying to match the mp/rpm at different altitudes, but mostly what it was about was descents… I’ve been used to pull on the throttle to start a descent and just let the plane pitch down and establish a descent rate while adjusting power/pitch. My CFI let me play with that but told me that in these planes you mostly pitch for descent while controlling airspeed to not exceed the standards.
And you are all 100% right - below 4-5k the throttle response was much more linear and controlled as I was practicing the approaches and landings.
Was mostly curious about that throttle response up higher which makes sense since it matches the poh power combinations when pretty much at full open.


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For VFR descents I leave the engine set at cruise power and trim for 500FPM.  You just need to plan accordingly so that you don’t find yourself entering the pattern behind the plane. Good to drop the gear abeam the numbers or at 2 miles out if not flying a standard pattern. Given your location you will be learning to manage power on cold, high pressure days. I’m betting Republic sometimes has DAs below -3000msl in the winter. 

[Hank]

2 hours ago, iamit said:

Wow, this is exactly what I was looking for here!
And yes - I was following the POH and trying to match the mp/rpm at different altitudes, but mostly what it was about was descents… I’ve been used to pull on the throttle to start a descent and just let the plane pitch down and establish a descent rate while adjusting power/pitch. My CFI let me play with that but told me that in these planes you mostly pitch for descent while controlling airspeed to not exceed the standards.
And you are all 100% right - below 4-5k the throttle response was much more linear and controlled as I was practicing the approaches and landings.
Was mostly curious about that throttle response up higher which makes sense since it matches the poh power combinations when pretty much at full open.

My C is carbureted, so I always reduce throttle at cruise; up high, only until the MP needle wiggles. Sometimes this can be 1/3 the travel on my quadrant.

Fly low one day, 1500-2000 agl, and look where the throttle is at 20" (about what I get at 10,000 msl); you'll need to move it that far before it reduces below 20" at that altitude. It's not "lag," but lack of atmospheric pressure as you close off the throttle opening. 

Descents are easy! I push the yoke for 500 fpm and spin the trim wheel to descend hands off and let the speed build. It's payback for the long, slow climb to altitude. As I come down, MP increases and so does EGT, so every couple if thousand feet I pull the throttle back.and push mixture forward to whatever the cruise values had been.

It's easy to count thousands of feet from pattern altitude to where you are, double it and add 2-3, then start down that number of minutes away. Level off, reduce throttle and slow towards pattern speed, lowering flaps when able. Enter the pattern and land.

Welcome to the club! Have fun learning your plane--Life with a Mooney is sweet!

[iamit]

2 minutes ago, Hank said:

My C is carbureted, so I always reduce throttle at cruise; up high, only until the MP needle wiggles. Sometimes this can be 1/3 the travel on my quadrant.

Fly low one day, 1500-2000 agl, and look where the throttle is at 20" (about what I get at 10,000 msl); you'll need to move it that far before it reduces below 20" at that altitude. It's not "lag," but lack of atmospheric pressure as you close off the throttle opening. 

Descents are easy! I push the yoke for 500 fpm and spin the trim wheel to descend hands off and let the speed build. It's payback for the long, slow climb to altitude. As I come down, MP increases and so does EGT, so every couple if thousand feet I pull the throttle back.and push mixture forward to whatever the cruise values had been.

It's easy to count thousands of feet from pattern altitude to where you are, double it and add 2-3, then start down that number of minutes away. Level off, reduce throttle and slow towards pattern speed, lowering flaps when able. Enter the pattern and land.

Welcome to the club! Have fun learning your plane--Life with a Mooney is sweet!

Thanks @Hank, this is precisely what I was looking for! I believe your comment about the lack of atmospheric pressure was right on as I do get that top 1/3 of the quadrant highly responsive down at the 4-5k altitudes once I've descended from the teens.

[A64Pilot]

It’s normal for there to be a sort of dead band at higher altitudes until the throttle is reduced enough to catch up if you will to ambient pressure.

I’m not saying if your WOT and 20” you have to pull it all the way back to where 20” would be at sea level, just that it’s just a little less sensitive is all.

Thirty years ago or there about when Commercial training in brand new M20AT I noticed when I trimmed her down at WOT for a 500 FPM descent she went right up to VNE, funny because the Pipers and Cessna’s I’d been flying didn’t do that  

Biggest thing to get used to in a Mooney is slowing one down soon enough, they are slick and if descending and trying to slow at the same time it may mean your reducing the throttle more than maybe you should, so you learn to start slowing further out. If I find myself a little too fast entering a pattern I’ll descend below pattern altitude then pitch up to climb back, and when pitched up she slows down quickly, then you can get gear and flaps, but I’m not one to drop gear at close to max speed. I think over time it’s hard on the gear doors etc.

[Shadrach]

24 minutes ago, Hank said:

My C is carbureted, so I always reduce throttle at cruise; up high, only until the MP needle wiggles. Sometimes this can be 1/3 the travel on my quadrant.

Fly low one day, 1500-2000 agl, and look where the throttle is at 20" (about what I get at 10,000 msl); you'll need to move it that far before it reduces below 20" at that altitude. It's not "lag," but lack of atmospheric pressure as you close off the throttle opening. 

Descents are easy! I push the yoke for 500 fpm and spin the trim wheel to descend hands off and let the speed build. It's payback for the long, slow climb to altitude. As I come down, MP increases and so does EGT, so every couple if thousand feet I pull the throttle back.and push mixture forward to whatever the cruise values had been.

It's easy to count thousands of feet from pattern altitude to where you are, double it and add 2-3, then start down that number of minutes away. Level off, reduce throttle and slow towards pattern speed, lowering flaps when able. Enter the pattern and land.

Welcome to the club! Have fun learning your plane--Life with a Mooney is sweet!

Sorry Hank but I have to disagree. Yes the air is less dense at altitude than it is at 1500 feet AGL. That does not mean that throttle movement required to reduce mp to 20” will be the same at both altitudes. I have flown on hot days above 12k where I could not even pull 20” and any throttle reduction affects MP. It’s just over a smaller range of available MP so the effect of the movement is less.  

3.5” of throttle travel to 0 to 29” down low. That same movement is spread between 0” and 20” at altitude, but the positions are not the same. Air is less dense by volume at altitude, the volume does not decrease.

[MBDiagMan]

Welcome ismit!  Not only to the forum, but to the world of the Mooney.  Moving from the Cessna/Piper world to a Mooney was a good move IMHO.  I’ve had my F for over four years now and had a C for a while before that.  I still enjoy my little Cessna taildragger for serious viewing of the lake on a pretty day, but the Mooney is the traveler.  I hope you enjoy yours as much as I enjoy mine.

[carusoam]

Welcome aboard URU!

Keep asking questions!

Go Mooney!

Best regards,

-a-

[EricJ]

On 10/8/2022 at 9:32 AM, N201MKTurbo said:

The OP asked about a throttle response issue, not about how to fly his plane.

Maybe he was trying to prove that a Mooney really does use less fuel going 120 KTS than a 172 or Cherokee.

A few months ago I took a buddy back to San Diego to retrieve his Cherokee 180 which was AOG.    We got it going and I followed him back along the southern route past Yuma.    It was painful to slow down that much.    I was playing with the power settings to see how low I could get the fuel consumption and still keep up.    He was flat out, because he always flies that way, and for a while I had it down to 5.6 gph and was still keeping up.   

[N201MKTurbo]

1 hour ago, EricJ said:

A few months ago I took a buddy back to San Diego to retrieve his Cherokee 180 which was AOG.    We got it going and I followed him back along the southern route past Yuma.    It was painful to slow down that much.    I was playing with the power settings to see how low I could get the fuel consumption and still keep up.    He was flat out, because he always flies that way, and for a while I had it down to 5.6 gph and was still keeping up.   

I’ve made that trip twice in formation with Brice, but I was the slow poke.

[EricJ]

Just now, N201MKTurbo said:

I’ve made that trip twice in formation with Brice, but I was the slow poke.

He was still probably burning more fuel than you.   

[N201MKTurbo]

1 hour ago, EricJ said:

He was still probably burning more fuel than you.   

3 times as much....