Best way to start a cold Mooney (M20C)

[BigD]

... taken from my 1965 M20C manual. I think I’ll skip the hand propping. Fuel pump? Seems like it might flood it. I’m curious to what some of you do?

 

 

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[cctsurf]

  Ninja hiding waiting for the fight to start  

[Boilermonkey]

Exactly as the POH states. Sometime it needs 2 more pumps of the throttle. You need the fuel pump to provide pressure... remember it's a low wing with now primer. If you depend on the engine driven pump it will take longer.

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[Hank]

I generally pull the prop through 2-3 revolutions, run the fuel pump until pressure stabilizes, pump the throttle 3-5 times, mixture Full Rich, turn the key and press. It often takes a little longer to catch if the engine has not been preheated. 

Note:  as temps fall, I give it more throttle pumps. Maybe 3 or 4 around freezing, 5 or 6 if <20°F.

This worked well for me along the Ohio River. Winter starts are much simpler in Alabama, although I still preheat occasionally instead of all the time.

[Andy95W]

You can't flood an M20C with just the fuel pump.  All you'll do is fill the carburetor bowl until the carb's float valve stops the flow into the carburetor. 

The problem with the M20C when it gets really cold- say below 25° or so- is fuel atomization.  The accelerator pump shoots gasoline up into the induction system but not enough of the gas vaporizes to suck into the cylinders so the spark can light it off.  Pumping the throttle while cranking helps this to a certain degree because it increases the chances that some of those airborne droplets will be sucked into at least one cylinder and ignited.

If that still doesn't work, you're going to have to preheat.  Warm metal will entice the fuel to vaporize.

[carusoam]

How cold is it where you are?

My M20C...

Below 30°F it takes a lot of pumps...

Below 20°F it took some pre-heating...

Flooding never happened... Excess fuel drained out of the carb and ran onto the tire...

Best regards,

-a-

[Guest]

One of the problems with the C model is the lack of an engine primer that most other makes have.

Clarence

[Mooney1]

Best way to start cold? Preheat! 

[jaylw314]

13 hours ago, Andy95W said:

You can't flood an M20C with just the fuel pump.  All you'll do is fill the carburetor bowl until the carb's float valve stops the flow into the carburetor. 

The problem with the M20C when it gets really cold- say below 25° or so- is fuel atomization.  The accelerator pump shoots gasoline up into the induction system but not enough of the gas vaporizes to suck into the cylinders so the spark can light it off.  Pumping the throttle while cranking helps this to a certain degree because it increases the chances that some of those airborne droplets will be sucked into at least one cylinder and ignited.

And using the throttle accelerator to pump gas into the carb risks gas leaking out the wrong way and the proverbial induction system fire.

I checked out in my old flight club Cherokee with the CFI in the club, who suggested pumping the throttle before cranking.  The next year when I did my BFR with my usual CFI, he watched me start and then very gently said, "You know, since you have a priming pump, I'd suggest using that instead of the throttle" and explained why.

I never realized the O-360's didn't have a primer, learn something new every day...

[cctsurf]

3 hours ago, jaylw314 said:

I never realized the O-360's didn't have a primer, learn something new every day...

O-360's can have a primer, Mooneys don't seem to have been fitted with it.  One minor difficulty is that the manifold pressure gauge uses a primer port for access to the manifold pressure at the cylinder head, this is not insurmountable...and has often been done.

[M20F]

11 hours ago, Mooney1 said:

Best way to start cold? Preheat! 

This is my answer as well, spend $1000 and get a Reiff Turbo Heater.   

[Oscar Avalle]

21 hours ago, Mooney1 said:

Best way to start cold? Preheat! 

That is what I do too. Without preheat start our planes in cold weather may be a real pain. Make sure your battery is in top notch and well charged. 

Mixture rich

Prop forward

Master on

Fuel pump on until you get pressure then off. 

Pump twice or three times, depending how cold it is 

THEN WAIT count until 30 (in my case I wait until the JPI loads)

crank and hope for the best. 90% of the cases she starts up

Then I put the alternator on line, Avionics Master on etc.

 

[DXB]

Preheating any time temp is below 50 degrees makes starting a snap, and no other tricks have worked reliably for me. Otherwise starting in 30s or 40s temps is a crap shoot in my hands, and any temp under 30 is near impossible. If it's not going well, don't just keep cranking and pumping.  Stop for a couple minutes to let some fuel vaporize and the starter cool off.  Then sometimes you get lucky with the next crank. If you get carried away with pumping the throttle like I used to, stop and look for fuel spilling out onto the nose wheel.  That means  push back into hangar and wait half an hour so you don't go up in flames. Taking off a side panel on the cowl and using a cheap space heater to blow hot air on the engine (use a sleeping bag or similar on top of cowl to duct the air) for just 20-30 minutes has worked great for me even in 20s temps. A more even preheat with the strongest dual oil pan and cylinder heater you can get (Rieff or Tanis) for at least an hour is probably much better for your engine though.

BTW O-360 hot starts shortly after shutting down in the summer have not been totally idiot proof for me.  The usual procedure tends to flood it. In that case, the POH flooded procedure works but takes some finesse to pull back on the throttle gently at just the right time.   A far better strategy is not to flood it in the first place by  leaving the mixture just half way in for the start.

[steingar]

Best way to start a cold Mooney is to warm it up first.

[Hank]

6 hours ago, Oscar Avalle said:

That is what I do too. Without preheat start our planes in cold weather may be a real pain. Make sure your battery is in top notch and well charged. 

Mixture rich

Prop forward

Master on

Fuel pump on until you get pressure then off. 

Pump twice or three times, depending how cold it is 

THEN WAIT count until 30 (in my case I wait until the JPI loads)

crank and hope for the best. 90% of the cases she starts up

Then I put the alternator on line, Avionics Master on etc.

 

Yep!

While waiting, I will put on my headset, then wind and set my yoke clock, aligning the red and white hands to track tank changes and flight time. It's usually good to go after that.

[Jcmtl]

I'm reviving this old thread as i'm currently having an issue starting my C.   It's up in Canada where the temps are around -3c or 26F.  I don't have access to pre heat.

I haven't been able to get the engine started and in the process the battery got completely drained.  So I'm coming here for help. 

What is consensus on starting a cold o-360.  From reading various threads it seems like the method of choice is boost pump on, mixture rich, let pressure build, boost pump off, 5-6 pumps of the throttle, 1/4 of the way open, wait 30 seconds, and then crank?  I may only have 1 or 2 shots at this (using booster pack), so I need something that will 100% work.  

I have the electroair left mag.

Any help is appreciated.  

p.s. the reason im desperately trying to get this thing going is to bring it to the avionics shop where it will stay for a few months, it's only a 5 minute flight so I'm not overly concerned about flying with a weak battery.  

 

[FlyingCanuck]

Not sure if this will help. But when I used to live in Canada, I owned a Cherokee with an O-320. Low wing, electric fuel boost pump. While it had a primer, that wasn't typically used. The one main difference between the advice so far (above) and my experience is that we always started that Cherokee with the boost pump ON. Mixture full rich, boost pump on. Sometimes 4-5 pumps of the throttle first too. Like others have said, if it doesn't start after ~10 seconds (which will feel like an eternity), stop. After 10 sec, it's not going to magically change its mind and start

The boost pump on + mixture full rich + a few pumps worked for the three years I owned it in Burlington (CZBA), with winter temps regularly below 0 deg C / 32 F.

That said, most of the time it lived in a hangar with a Tanis engine heater and a horse saddle blanket on the cowl.

Are you sure you can't get access to an electrical plug to heat it up? I've seen Mooneys sitting on the ramp with the better part of 100' of electrical cord leading to a plug somewhere. 

Cold starts are really hard on the engine. When I was visiting family in Toronto last week and parked at Buttonville (CYKZ), I would pay the $100 for a night in a heated hangar before flying the next day. It hurt the wallet, but I figured I was probably doing somewhere between $25-$100 of wear on the engine with every very cold (below zero C) start anyway.

[Greg Ellis]

1 hour ago, Jcmtl said:

I'm reviving this old thread as i'm currently having an issue starting my C.   It's up in Canada where the temps are around -3c or 26F.  I don't have access to pre heat.

I haven't been able to get the engine started and in the process the battery got completely drained.  So I'm coming here for help. 

What is consensus on starting a cold o-360.  From reading various threads it seems like the method of choice is boost pump on, mixture rich, let pressure build, boost pump off, 5-6 pumps of the throttle, 1/4 of the way open, wait 30 seconds, and then crank?  I may only have 1 or 2 shots at this (using booster pack), so I need something that will 100% work.  

I have the electroair left mag.

Any help is appreciated.  

p.s. the reason im desperately trying to get this thing going is to bring it to the avionics shop where it will stay for a few months, it's only a 5 minute flight so I'm not overly concerned about flying with a weak battery.  

 

I am not sure if this is your issue.  Being from Texas, I rarely have to start below 40 and if is below 40 I usually don't feel like going to the airport.  However, 100LL does not vaporize well at very cold temps.  The reason you wait 30 seconds is for the fuel to vaporize so it will burn.  Your 30 seconds may not be enough in the extreme cold you are dealing with.  Warming the engine first will help.  It will also help to get the oil moving quickly.  Each time you crank it over with that cold of an engine you are just losing longevity on your engine.  Metal is scraping on metal with no oil barrier because the oil can't get moving quick enough to coat the parts because it is basically syrup.

So, I would suggest to try your best to get the engine heated prior to starting.  Just my $.02 (USD not Canadian)

[Jcmtl]

Greg your $.02 USD is worth more than ours and i agree with you.   

That said, it will be +10 this weekend so i'll try it again, but this will be my last shot to get the plane in the air, so I need this to work. 

 

[DXB]

1 hour ago, Jcmtl said:

I'm reviving this old thread as i'm currently having an issue starting my C.   It's up in Canada where the temps are around -3c or 26F.  I don't have access to pre heat.

I haven't been able to get the engine started and in the process the battery got completely drained.  So I'm coming here for help. 

What is consensus on starting a cold o-360.  From reading various threads it seems like the method of choice is boost pump on, mixture rich, let pressure build, boost pump off, 5-6 pumps of the throttle, 1/4 of the way open, wait 30 seconds, and then crank?  I may only have 1 or 2 shots at this (using booster pack), so I need something that will 100% work.  

I have the electroair left mag.

Any help is appreciated.  

p.s. the reason im desperately trying to get this thing going is to bring it to the avionics shop where it will stay for a few months, it's only a 5 minute flight so I'm not overly concerned about flying with a weak battery.  

 

You gotta pre heat here! No way around it. But that will 100% work. And not doing so is incredibly destructive to your engine at those very low temps, even if you somehow get it started, which seems unlikely.

Get a long extension cord or a gas generator if its out on the ramp.  If you have nothing better, place a small space heater on a stool at the level of the engine.  Take a cowl cheek panel off.  Cover everything  with a sleeping bag including the heater (carefully so as not to risk fire).  Run the heater for a couple of hours at least. Then use your standard starting procedure. 

Edited December 7, 2021 by DXB

[Raptor05121]

Preheating will not only lessen wear on the engine, but make starting 100% easier.

If you are draining a battery not being able to start it, I'd hit the starter and just pump like crazy unless you've been able to verify you have a good accelerator pump.

[N201MKTurbo]

You can always add a couple of cups of avgas to the crankcase. It will thin the oil and the engine will crank much easier. This was an option back in the day.

When I first started flying Mooneys, I was flying for service calls out of Denver. I parked outside and would only get a preheat if I couldn’t get it started. When I got to my destination, I would just park on the ramp. In many cases that was the only option. The plane would cold soak for hours while I was working. I always got it going again. When I rebuilt that engine I couldn’t find anything I could attribute to cold  starts.

A flooded start was your best bet if a normal start didn’t work. Set your RPMs to 1500 until your oil pressure stabilized, and the oil temp gets above 60. Then go fly as normal. 

[Prior owner]

When I worked out of Yakima, WA many years ago, the owner of the aircraft used something like this to warm the recip engine in our helicopter outside in the winter. It worked very well- he attached a length of steel duct on the end and directed it under the engine. Your could probably get a piece of cheap steel duct with a divider and run two large scat tubes  from it plugged into each cowl vent…? If you are outside and don’t have access to any power.

Cordless Forced air propane heater

 

 

[jamesm]

Here to throw a monkey wrench to topic. Please correct me if I am incorrect (as I am sure you will   )

What about the starter and Ignition setup and Of course the fuel delivery system plays a vital part  in starting but the design hasn't changed (that I know of) since Mooney's M20C were being built.

When Mooney first delivered the M20C's in the 60's with old Prestolite starters  and  Bendix/Garwin Shower of sparks (and some other supplier)and massive electrode plugs. While approved ignition system  and plugs hasn't changed too much, but I have notice some owners elected to with slick mag with impulse couple mag installation for the starting mag. John Schwaner( Sac Sky Ranch) took time to educated me on the simplicity of the Shower of sparks system, So I guess I am biased toward the shower of sparks system.  This is an effective starting method for period of the time we were in. However with aging wiring and  connections, mechanical points, springs and even impulse coupled mag spring wear a time goes on.  I start to wonder not if it the starting system will fail but when and what are the signs of impending not be able to start the engine. There is advent electronic ignition  but still fairly new in the certified aircraft world but time will tell.

I had a real fear when starting the Mooney in the mid 90's. My father whom  inherited the Mooney from  who was an engineer and P-38 pilot in WWII would seem to always get the Mooney started. but I do remember a couple of times where the Mooney giving him a bit a trouble and even he struggled. My fear was that I would fly into a remote strip someplace  where I would get stranded. And I wouldn't able to get it started again.

I can't speak for other starter manufactures,  Skytec and I am sure manufactures are as good, at least ones that took the time redesign and addressed the starter's point failure and not just re-badge them with a different name.

I have heard some say  the speed  at which  starter spins the prop has no effect on whether planes starts or not. I suppose if isn't getting fuel  that might be the case.

The new starters ability to throw prop blades with such speed is impressive.  I don't know how to verify  the effectiveness of the rate at which prop turns during start up is  in play during starting procedure in hold or cold weather environment. Seems several variables come into play during start up (stating the obvious).

 Curious other peoples thoughts

[Ragsf15e]

And you guys all make fun of us IO-360 guys and our 100s of hot start techniques!  Ha!  Cold start is easy in the IO! 

(FWIW, find a way to preheat).