What is best way to start a flooded engine

[rockydoc]

Recently after not flying for a month, I ran the batter down on my M20B trying to start it after, I am presuming, flooding the engine.  I know I have read the best procedure for starting a flooded engine, but can't remember it.  Can you guys help by telling me the best way to do it?

[Bob_Belville]

This is SOP for the IO360 which probably will work with your O360. 

 

Flood engine start procedure for the IO-360 in the M20E ·         Master switch on  ·         Throttle, prop and mixture full forward ·         Boost pump on 3 seconds, then off ·         Mixture to IDLE/CUTOFF ·         Throttle full OPEN ·         Engage the starter  ·         Slowly pull the throttle back towards idle as the engine is turning over with the starter engaged  ·         When the throttled is reduced to about ½ to ¾ towards the idle position, the engine should fire after the throttle hits the position for the perfect fuel/air mixture for starting ·         When the engine fires, smoothly increase the mixture to full rich ·         Bring the throttle back to the normal idle speed (1000-1100RPM) ·         After idling awhile, lean the mixture for smooth operation on the ground and during taxi

[rockydoc]

 

This is SOP for the IO360 which probably will work with your O360. 

 

Flood engine start procedure for the IO-360 in the M20E ·         Master switch on  ·         Throttle, prop and mixture full forward ·         Boost pump on 3 seconds, then off ·         Mixture to IDLE/CUTOFF ·         Throttle full OPEN ·         Engage the starter  ·         Slowly pull the throttle back towards idle as the engine is turning over with the starter engaged  ·         When the throttled is reduced to about ½ to ¾ towards the idle position, the engine should fire after the throttle hits the position for the perfect fuel/air mixture for starting ·         When the engine fires, smoothly increase the mixture to full rich ·         Bring the throttle back to the normal idle speed (1000-1100RPM) ·         After idling awhile, lean the mixture for smooth operation on the ground and during taxi

 

Bob, thanks for the help.  I printed it out and will keep it on my kneeboard.  Dave

[orionflt]

I like what bob posted except if you are flooded, you do not need to run the boost pump to pressurize the fuel system, all you are doing at that point is dumping excess fuel overboard.

[DaveL]

I usually just pull the throttle wide open and let the plane sit for fifteen minutes at least. After that I start as usual.

[MooneyMuscle]

From my experience, a solid battery and a skytec starter...you wont have an issue.

[Hector]

I've always heard of flooding issues with the IO360, but I've yet to experience it in my 67C (O360). Are you sure you don't have a weak battery? Cold start in my O360 consists of mixture rich, boost pump on, pump the throttle twice and push it in about 1/2 inch , prop full forward, hit ignition and it starts in two turns. Hot start is the same but I don't pump the throttle at all or maybe just once. Starts right away every time.

Sent from my iPad using Tapatalk HD

[Seanhoya]

Rockydoc - Starting an O-360s can be tricky.  Bob has some good advice, but I would like to add that starting a carbuerated engine requires that you learn the temper of your specific engine and carbuerator - it is a bit different from aircraft to aircraft.  In fact, the best advice I ever got about starting my Mooney came from my father, based on his experience starting a '53 Chevy growing up.  He actually deserves the credit for us starting on a cold morning recently in Charlotte, NC, and being able to complete our cross country adventure (hint - if it is really cold, don't worry about flooding a cold engine.  Repeat the standard procedure until it starts, and maybe start with four pumps of the throttle, vice three).  

 

Long story short - I have this problem all the time, dude, and especially so in cold weather on hot engine starts.  I have posted the POH procedure below, and it works. It basically involves putting the throttle full forward, the mixture at idle, and no fuel pump, and cranking until the engine turns over.  Once it turns over, it takes some quick hands to retard the throttle, then enrichen the fuel mixture.  Honestly, I have never turned the fuel pump on at that point.  Here's the clincher - if you run down your battery, don't give up.  Turn off all loads, and wait a minute or two.  Then turn the prop over once.  If the prop has some "spring" to it, that means that it is actually igniting, and it is a great indication that you have flooded the engine.  Keep this up three or four times, and the engine will start.

 

A word about hot starts - no fuel pump, one pump of the throttle, and keep the mixture leaned like you do on the ground to start.  If this doesn't work on the first try, you have already flooded the engine.

 

Clear skies!

 

Sean

 

From 1968 G Model POH, Page 3-8: Flooded Engine Clearing

 

Throttle - Full Open

Mixture - Idle Cutoff

Electric Fuel Pump - Off

Ignition - Turn to Start and Press Forward

Throttle - Retard when engine starts

Mixture Control - Open slowly to full rich

Electric Fuel Pump - On

[Shadrach]

How do you know that you flooded it?  What was the OAT?  While an engine can be flooded on a cool morning, it takes a fair amount of fuel. I can just set my mixture at full rich and crank when the OAT is <35df.

[Matt Ward]

On 12/27/2013 at 10:22 AM, Shadrach said:

How do you know that you flooded it?  What was the OAT?  While an engine can be flooded on a cool morning, it takes a fair amount of fuel. I can just set my mixture at full rich and crank when the OAT is <35df.

Sorry to dig up a seven year old thread, but, what is the answer to this question? The reason I ask is this:1966 M20e, newly OH fuel pump. Cold crank this morning (Denver, 40 degrees) was fine. Ten minutes of taxi, shut down, check fuel pump for leak out of the tattle tale. 3-5 minutes of shutdown. Go to restart and decide to use hot start, no luck. Then decide to use flooded. No luck. Tried 4 or 5 times I think with the flooded start procedure. But I did manage to flood it! I only know that because I got out to check the sniffle and saw a pile of avgas on the ground. How would I have known from in the cockpit? Would it be because the hot start wouldn’t get a cough? Fuel pressure above zero? Any clues to help me know which starting technique to use would be greatly appreciated!

[Tahir K]

this articled helped me a lot.


http://mooneypilots.com/mapalog/HOT%20STARTS.htm

[Matt Ward]

Yup, that’s my “how to”; I just need the “when to”. 

[gsxrpilot]

I really can't contribute much here as the engine on my Mooney is a different type of beast. But it does have a mixture knob and I've learned since moving to Denver that when starting, or anytime I'm on the ground with less than full throttle in, I should treat an inch pulled out, to be full rich. My engine won't start or stay running with the mixture at full rich, at this altitude. 

[mike20papa]

If you have not flown in months - there's a chance no fuel in the carb bowl.  turn the master on, turn the aux. fuel pump on till you see a few pounds psi.  turn it off.  pump the throttle (acc. pump) about 4 full strokes.  mixture rich, crack the throttle, make the left mag hot then hit the starter.  good luck.

Also, not a bad idea to pull the top plugs, spin the engine and pre-oil the motor. especially when it's been sitting for a while.

[carusoam]

It’s all about experience...

Take notes as you go, Matt!

Often...

• really cold starts... are below <20F 100LL doesn’t evaporate very well...at all...
• Cold starts... <40F pre-heat is suggested... Extra prime is warranted... Because 100LL evaporates slooowly...
• ordinary starts... minimum prime is used... makes sure Fuel is getting to the engine... 100LL evaporates well...
• warm starts...just like an ordinary start... using extra caution to not over prime (don’t prime at all)
• Engine was running to taxi.... Is a warm start... but the fuel system is empty because you just pulled the mixture... (put the fuel back)
• Hot start... The CHTs have Been run up around 400+°F while doing pattern work, and you hear the fuel boiling in the injection system from under the cowl... (100LL evaporates too well when hot, and The bubbles push the liquid down the tube... into the cylinders when not asked for...)
   

If you don’t hear the fuel boiling... probably not a hot start...
a good long descent from altitude... Probably not a hot start...

Plane has been sitting long enough to get comfortably refueled... probably not a hot start...
You ate lunch Since you landed... not a hot start...

Doing lots of pattern work on a hot summer day... needing to refuel... CHTs are high, injector system is boiling, you open the oil door on the cowl Just to let hot air out...   You jammed 10gal per side in and run to get back in the seat... expect it to be your lucky day... do the hot start!   
 

When you can’t figure it out... flood it... do the flooded start before the battery croaks...

Remember when changing Mixture settings while starting the engine... you can hear each compression stroke... don’t be too Fast....

 

PP thoughts to consider... 

Best regards,

-a-

[Tahir K]

It’s all about experience...
Take notes as you go, Matt!
Often...

• really cold starts... are below
• Cold starts...
• ordinary starts... minimum prime is used... makes sure Fuel is getting to the engine...
• warm starts...just like an ordinary start... using extra caution to not over prime (don’t prime at all)
• Engine was running to taxi.... Is a warm start...
• Hot start... The CHTs have Been run up around 400+°F while doing pattern work, and you hear the fuel boiling in the injection system from under the cowl...
   

If you don’t hear the fuel boiling... probably not a hot start...
a good long descent from altitude... Probably not a hot start...
Plane has been sitting long enough to get comfortably refueled... probably not a hot start...
You ate lunch Since you landed... not a hot start...
Doing lots of pattern work on a hot summer day... needing to refuel... CHTs are high, injector system is boiling, you open the oil door on the cowl Just to let hot air out...   You jammed 10gal per side in and run to get back in the seat... expect it to be your lucky day... do the hot start!   
 
When you can’t figure it out... flood it... do the flooded start before the battery croaks...
Remember when changing Mixture settings while starting the engine... you can hear each compression stroke... don’t be too Fast....
 
PP thoughts to consider... 
Best regards,
-a-

Would you say it's a bad idea to just always go straight for the flooded start to not have to deal with a failed hot start/dead battery?

[carusoam]

Tahir,

Typically, I get one try at it... if it works... I Look like I know what I’m doing...
 

If I need a second try it is on its way to the flooded start anyway... 

With my IO550... it very often isn’t getting enough fuel...

I haven’t figured out a way to really know one way or the other...
 

So err to the too much fuel side... expecting it to start...  

Then flood it, knowing it will start with the flooded procedure...

 

The fancy thing about the Continental fuel system... with the mixture pulled, and the fuel pump running... cool fuel can be circulated back to the tanks... cool fuel doesn’t evaporate too quickly, like the heated fuel can...

 

The only reason I would prefer not to flood it intentionally... fuel dripping on the ground below a really hot engine could Lead a different challenge... the uncontrolled burn of the external combustion engine...  

PP thoughts only...

Best regards,

-a-

 

[PT20J]

Don't make this too hard 

Engines only run with a fuel-air mixture within a fairly narrow range. Either way -- too rich or too lean -- and they won't start. But sometimes it's hard to tell if it's not starting because it's too rich or too lean and you can run the battery down (or burn up the starter) going back and forth trying to guess which it is. The best thing to do is prime until you know it's flooded. Then you want no more fuel (mixture ICO) and a lot of air (wide open throttle) and crank until it fires. Then reduce the throttle and full rich mixture to keep it running.

Skip

[carusoam]

+1 narrow margin between too rich and too lean...

The advantage of the flooded start...

• it starts out too rich... (known place to start)
• The procedure sweeps it through the whole array from rich to lean...
• The engine starts when the mixture is just right....
• Just don’t move the knob too fast compared to the number of blades going by.... you may skip the just right position...

Best regards,

-a-

[Pasturepilot]

11 hours ago, carusoam said:

 

When you can’t figure it out... flood it... do the flooded start before the battery croaks...

 

Years ago I was trying to start a hopped up IO-360 in an aerobatic bird to taxi it shortly after the performer had flown his routine. I was getting nowhere, fast. 

The pilot walked over and uttered some fateful words: "When in doubt, flood it out." At least then, you know what you're dealing with. It's served me well in a lot of types that I didn't fly long enough to build aircraft-specific knowledge in. 

Also, if you start seeing any sort of starting issue regularly, it might be time to take a long, hard look at your ignition system. That's where it often first starts showing age. A weak spark amplifies any other issues at startup. 

[Ragsf15e]

11 hours ago, Tahir K said:

Would you say it's a bad idea to just always go straight for the flooded start to not have to deal with a failed hot start/dead battery?

Actually, no, I wouldn’t recommend that.  I think this answer is going to be in line with Skips and Carusaum, even though they didn’t say it exactly... if in doubt, go for a hot start first.  You give that one good shot.  If that doesn’t work, follow Skips advice for flooding it to know where you’re at and do a flood start.

You only get one shot at a hot start, and once you prime, you can’t go back.  You can always flood it.

@Marauderhad a good story of a tailpipe fire after a flooded start. Now that’s pretty rare, but enough for me to give hot start a chance.  Honestly hot starts probably work 99% for me.  The question of 3-5 minutes idle then shutdown would be tough, but I’d probably try hot start first.  If in doubt...

[R-Banger]

13 hours ago, Ragsf15e said:

Actually, no, I wouldn’t recommend that.  I think this answer is going to be in line with Skips and Carusaum, even though they didn’t say it exactly... if in doubt, go for a hot start first.  You give that one good shot.  If that doesn’t work, follow Skips advice for flooding it to know where you’re at and do a flood start.

You only get one shot at a hot start, and once you prime, you can’t go back.  You can always flood it.

@Marauderhad a good story of a tailpipe fire after a flooded start. Now that’s pretty rare, but enough for me to give hot start a chance.  Honestly hot starts probably work 99% for me.  The question of 3-5 minutes idle then shutdown would be tough, but I’d probably try hot start first.  If in doubt...

Yeah I always go for one hot start, and then flooded if it doesn't fire. I don't recall ever getting a 2nd attempt at a hot start that actually fired.The procedure prescribed with full throttle and slowly retarding with cranking is rock solid. For hot starts the electric fuel pump is critical as the it gets pretty hot under that tight cowl, same goes for going nice and slow with the mixture when it fires.

[Ragsf15e]

5 minutes ago, R-Banger said:

Yeah I always go for one hot start, and then flooded if it doesn't fire. I don't recall ever getting a 2nd attempt at a hot start that actually fired.The procedure prescribed with full throttle and slowly retarding with cranking is rock solid. For hot starts the electric fuel pump is critical as the it gets pretty hot under that tight cowl, same goes for going nice and slow with the mixture when it fires.

Interesting, I don’t use the electric pump at all on my hot starts.  

[R-Banger]

2 hours ago, Ragsf15e said:

Interesting, I don’t use the electric pump at all on my hot starts.  

Yeah if it sits with the heat in the dog house the fuel vaporizes. I can get it started without it sometimes, but every once in a while she sputters and fuel pressure will drop. Usually happened right as it starts to catch and then would starve itself. Hit that boost pump and it helps get past the hurdle no hiccups. Prop gets some air flowing through there and then pump off, fuel pressure doesn't even twitch. 

[ReconJon]

Do a solid run up. They tend to spit and backfire for a bit. Dont want that on takeoff.