M20J - in search of quicker starts

[ArtVandelay]

I follow the POH, ...full rich, fuel pump to est. pressure, ICO; It takes maybe 5 seconds before it actually starts...

on youtube there is a vid of 172SP cold start:

It starts much quicker, uses fuel pump then mixture, so I tried it, but it didn't shorten my startup time.

 

Why mixture is in ICO position on start? seems counterintuitive.

 

I tried leaving the mixture in full rich position, that didn't seem to help either.

After it starts, it runs fine.

 

Clearly I'm not the only one:

 

 

[PTK]

This is my cold start:

Fuel selector fullest tank, mixture full rich, fuel pump on for 8 sec then off, mixture ICO, throttle is already at ~1000 RPM from previous shutdown, turn key. Ready with mixture rich once she fires. Then lean brutally for ground ops.

Fires up in one blade.

[Guest]

I start them all the same way whether a Lycoming or a Continental:

throttle wide open, mixture full rich, fuel boost pump on till flow or pressure indicate, pump off ,throttle to idle then cracked 1/16 to 1/8" open, crank engine. A healthy engine should start from cold in a few blades.

From experience I've found that 200 HP Lycoming engines flood quite easily.

Clarence

[Bartman]

For cold starts I have found it useful to wait about 15 seconds after turning off the boost pump. I think this allows the fuel to vaporize and it does start quicker for me. The ONLY time mine ever starts on one blade....is on the second attempt.

[ArtVandelay]

This is my cold start:

Fuel selector fullest tank, mixture full rich, fuel pump on for 8 sec then off, mixture ICO, throttle is already at ~1000 RPM from previous shutdown, turn key. Ready with mixture rich once she fires. Then lean brutally for ground ops.

Fires up in one blade.

Wow, 1 blade, do you wait at all for the fuel to vaporize as Bartman mention?

Do you move the mixture to rich slowly, or just push it in as in the 172SP video?

When you say fire, mine sounds more like it's coughing, and fires up only after push the mixture in, it's like it doesn't have enough fuel to run, which kinda make sense. I assume the full 8 seconds fixes this problem.

[Marauder]

My summer and winter cold starts behave a bit differently. I follow the same procedure Pete does. In the winter, it is usually a blade or two before start. In the summer, I find that I need more cranks before it fires. I often wonder if it is a stoichiometric thing where the ratios change a bit in warmer temps.

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[carqwik]

Not a Bravo in the video...per the FAA registry, that's a M20C....

 

The Bravo does generally start pretty quickly though...at least mine does although it can get balky when hot.

[jetdriven]

I start them all the same way whether a Lycoming or a Continental:

throttle wide open, mixture full rich, fuel boost pump on till flow or pressure indicate, pump off ,throttle to idle then cracked 1/16 to 1/8" open, crank engine. A healthy engine should start from cold in a few blades.

From experience I've found that 200 HP Lycoming engines flood quite easily.

Clarence

 

So do I, and if I'm even slightly familiar with the plane, I can get lightoff in 2-3 blades.

 

The no-touch crank method takes longer and theres no way around it unless you get a lightweight starter. My boss has one an an Arrow, and a pilot borrowed it, he got a call it wouldn't hot start. We took the starter off, and I kid you not, the brushes and the armature were a pool of molten metal in the bottom of the starter housing.  Ten seconds maximum cranking time?  I like my Prestolite tractor starter.

[PTK]

Wow, 1 blade, do you wait at all for the fuel to vaporize as Bartman mention?

Do you move the mixture to rich slowly, or just push it in as in the 172SP video?

When you say fire, mine sounds more like it's coughing, and fires up only after push the mixture in, it's like it doesn't have enough fuel to run, which kinda make sense. I assume the full 8 seconds fixes this problem.

Mixture full rich quickly with no delay once she fires.

[Jeff_S]

Here's a general rule of thumb I read from Mike Busch which seems to hold true. Trouble cold starting: not enough fuel. Trouble hot starting: too much fuel.

 

It seems to me the video in the OP was a hot start...the behavior of that plane was more consistent with a hot start.

 

I do just like everyone else in the J and it generally fires up in just a second or two.

 

I'll have to relearn how all this works with a big-bore Continental...subtle announcement about a new piece of rolling stock in my inventory!

[Hondo]

Hot start was the hardest to get right.

 

STARTING                 Normal                  Hot                        Flooded

Prop.............................IN............................IN...........................IN

Mixture........................RICH......................AFT........................AFT

Throttle.......................AFT 1/4 “ ...............AFT 1/4”.................IN

Master switch.............ON Confirm LOW VAC and ALT warning lights

Boost pump................ON ~5 secs...........OFF........................OFF

Mixture........................AFT.........................AFT........................AFT

Propeller area............CLEAR..................CLEAR..................CLEAR

Ignition........................Start........................Start........................Start

Mixture at firing..........AFT........................Moving in................AFT

Mixture after firing.....AFT 1”...................Rich then AFT 1”,,,,AFT 1”

RPM............................800 - 1000

Oil pressure...............GREEN WITHIN 30 SECONDS OR SHUTDOWN

[John Pleisse]

12 secs of fuel below 60 degrees, cold. About 6 sec's in the hot summer. It's hard to flood in the winter, but easy to flood in the summer. I have a high speed starter with a long service history. It completely ended burning up batteries. It was worth the money. 2 blades and it fires....every time.

[Awqward]

It is pretty clear that when you haven't run the engine for several hours it is a Cold Start. Likewise when you land shutdown and refuel say within 20 minute it's a Hot Start.....totally different techniques.....BUT when does the transition in techniques occur? Is it by reference to the CHT? For example I shutdown on a relatively hot day 90F+ and return 30 minutes later, or 40 minutes or an hour....it seems that if you use Hot start when the engine is cold or Cold start when engine is "warm" will result in a failure to start.....what have others found?

Anthony

[jetdriven]

 

Hot start was the hardest to get right.

 

STARTING                 Normal                  Hot                        Flooded

Prop.............................IN............................IN...........................IN

Mixture........................RICH......................AFT........................AFT

Throttle.......................AFT 1/4 “ ...............AFT 1/4”.................IN

Master switch.............ON Confirm LOW VAC and ALT warning lights

Boost pump................ON ~5 secs...........OFF........................OFF

Mixture........................AFT.........................AFT........................AFT

Propeller area............CLEAR..................CLEAR..................CLEAR

Ignition........................Start........................Start........................Start

Mixture at firing..........AFT........................Moving in................AFT

Mixture after firing.....AFT 1”...................Rich then AFT 1”,,,,AFT 1”

RPM............................800 - 1000

Oil pressure...............GREEN WITHIN 30 SECONDS OR SHUTDOWN

 

thats more items to remember than the 747 limitations section.  Quite a cookbook.

[Awqward]

The "Mixture at Firing" for the Hot start is a new one for me....will have to try it...hot starts are still killing me (and my starter...and my battery)

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[Awqward]

I meant "mixture fate firing" ie full then back an inch

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[Super Dave]

It is pretty clear that when you haven't run the engine for several hours it is a Cold Start. Likewise when you land shutdown and refuel say within 20 minute it's a Hot Start.....totally different techniques.....BUT when does the transition in techniques occur? Is it by reference to the CHT? For example I shutdown on a relatively hot day 90F+ and return 30 minutes later, or 40 minutes or an hour....it seems that if you use Hot start when the engine is cold or Cold start when engine is "warm" will result in a failure to start.....what have others found?

Anthony

If in doubt, I always try the hot start first. That way, if it doesn't start I know that I now need to try a cold start.

If you try the cold start first and it doesn't work, now you have to guess if it needs a hot start, flooded start, or another cold start.

[PTK]

If you attempt a cold start on relatively hot engine you run the risk of flooding it. Then you'll need the flooded engine start!

Use your judgement. On a hot summer day it'll take longer to cool down than in colder weather.

[Awqward]

I've recently gotten Hot starts figured out...thanks to advice from MS and the MAPA List.....However I had another bad day yesterday (ran the battery down and needed recharging THREE times....) the plane had been sitting for 2 days on the ramp (not my home airport) and I didn't refuel on arrival because I was in a hurry....on returning to the airport (with my wife and two kids) to return home I started and taxied over to the fuel pumps while they had some lunch....I then refueled and they all got in for the two hour trip home....then the nightmare began! I used the hard-learned Hot start technique that has been working perfectly for me recently (when the engine was truly Hot)...I had idled at 1100 before shutting down and not touched the throttle...mixture left at ICO...cranked....started gradually moving the mixture in after about 6 seconds....fail...tried again from ICO....fail...repeated until battery died...after repeating above one more time (second recharge)...I pushed throttle forward with mixture at ICO...ignition off...hand pulled through 16 blades (8 revolutions) to clear the cylinders (as advised by an Arrow pilot trying to help)....then went to Cold start technique...failed...then I boosted to flood and tried Flooded technique....it fired and ran....but quit after about 6-7 seconds!....tried again...fail...battery recharge (third time)....this time waited an hour before trying again...and pulling prop through by hand...Cold start failed....Flooded start got it going....and this time it managed to hang on and keep going although for about 30 seconds it felt like it would quit before it got firing on all cylinders....so after sending 3 DLA messages and finally canceling my IFR flight plan and refiling we departed Four hours late with my wife and kids totally unimpressed!

So my takeaway from the above drama is that Cold starts are fine, true Hot starts are fine...but Luke Warm starts are to be avoided at all costs! I was able to put my hand on the no2 cylinder from the beginning...so Not hot...just flooded I suppose...totally humiliation!

[Guest]

I would be very worried about internal damage to any engine that drained a battery three times before starting. Your camshaft and many other internal part depend on splash lubrication not pressure lubrication.

I would consider having your ignition system checked over, spark plug internal resistance, ignition wire resistance, clean ends and springs of all wires, and finally magneto 500 checks and magneto to engine timing. All of these are cheaper than engine damage.

Clarence

[aaronk25]

So I think our engines are a bit more finicky to start compared to the 180hp, injected 172 because the higher compression ratio results in a bit slower cranking speed. We've all heard these engines crank.....woof..woof....woof. The 172 will almost crank over over at run up speed....well not really. When cold starting I make sure to prime just enough to start but always error on conservative side so if it doesn't fire in a few blades I can keep the starter actuated and hit the boost pump. Keep in mind I deviated from the POH and left the mixture full rich so the boost pump will get the required fuel to the engine. If left in this condition it would quickly flood if the starter wasn't cranking but the beautiful thing with this method is the engine never gets flooded and when the fuel does hit the cylinders it starts and fuel is never more than 2-3seconds away even if I severely under primed the engine and starter crank time never exceeds 7 seconds so I don't risk cooking my light weight starter. Interesting thing what really screws a lot of people up is the engine requires less prime in winter than in summer....because in summer after shut down the hear from the engine boils the fuel out of injection lines where in the winter it's cold enough that it doesn't boil the fuel. I think it takes about 2-3seconds if prime just to get the fuel lines refilled with fuel. I think if it's 30 degrees or colder it doesn't boil the fuel out.....ever heard that gurgling sound after shut down? In winter 3sec of prime is plenty (assuming it was flown in last 7 days). In summer it takes 5-6seconds of prime. There has been times in summer when I SWORE that I had it flooded but darn it, it wasn't just wasn't any fuel in the cylinders.... In MN you learn how to cold start a engine prime/choke or your ass isn't gonna blow snow, start the snowmobile or whatever it is your trying to do. Still don't know why I live here. YMMV.....and this info might be worth exactly what you paid for it....but darn if don't retract your flaps on landing

[kevinw]

This is my cold start:

Fuel selector fullest tank, mixture full rich, fuel pump on for 8 sec then off, mixture ICO, throttle is already at ~1000 RPM from previous shutdown, turn key. Ready with mixture rich once she fires. Then lean brutally for ground ops.

Fires up in one blade.

I'm going to try this next time. It hasn't worked well in the past but I only hit the fuel pump for about 3 seconds out of fear of flooding it. Thanks for the info!

[Alan Fox]

Cold start for "E" Mixture and throttle all the way in , Boost pump until the pressure needle stabilizes (about 3 to 4 seconds ) throttle all the way out and then push it in about 1/4 inch, crank and one blade it starts ....  Every time cold..... Hot starts are a different story...

[PTK]

I'm going to try this next time. It hasn't worked well in the past but I only hit the fuel pump for about 3 seconds out of fear of flooding it. Thanks for the info!

Understand that's a COLD start. As in first start of the day for example. Use your judgment. I count about 8 mississippi's or so max with boost pump.

For hot start: Throttle is at ~1000 RPM or so from last shutdown and mixture is ICO. I don't touch anything. Simply turn the key.

When she fires, which is typically in a couple blades, in comes mixture helping her smooth out. Don't need full mixture. Just enough to smooth her out. Again use your judgment as to how hot is hot and apply some variation either way.

Always lean brutally for ground ops.

[ArtVandelay]

Cold start for "E" Mixture and throttle all the way in , Boost pump until the pressure needle stabilizes (about 3 to 4 seconds ) throttle all the way out and then push it in about 1/4 inch, crank and one blade it starts ....  Every time cold..... Hot starts are a different story...

you leave mixture all the way in??