Hot start procedures for IO-360

[jaylw314]

2 hours ago, ArtVandelay said:

How does slickstart fix hot starts because hot starts are a fuel supply problem, not a spark problem?

It doesn't, he was referring to @thomas1142 talking about his mags being wonky.

 

2 hours ago, LeRoy Johnston said:

Great discussion--My mechanic (who owned an M20J for years), deliberately floods it so every warm start is a flooded start.  The idea is to start from a known condition.   We tried that too and it worked for me the first time but not the next day.   It's a little sporty because you need to be ready to back off the throttle.   Because it is not starting 100 percent reliably, we are going to do a complete ignition service--overhaul mags (at 500 hours they are due now anyway), new plugs with fine wires on the bottom, and of course set timing and check engine controls.  We know it's getting air and fuel, so this may be the answer.   I have learned a lot about the system from reading these posts, for which I am indebted to you all.  --LeRoy 

Sounds like you're making all the right moves.  If you trust whoever's doing the mags, ask them to IRAN them instead of overhauling them (saves a few dollars).  My shop does a lot of mag work and has the test stand, and when I had hard starting problems a few years back, my A&P said he was surprised I could get started with the left mag so weak.  The mag was only 250 hours since new, but when he IRAN'd it there was sufficient where to mess up the internal timing.  Resetting it fixed pretty much every single starting problem.  I can't remember any time since then where any kind of start was a problem.

The Bendix RSA fuel injection system is a super interesting bit of engineering and cool to read about!  I think it's a cousin to the pressure carburetors a lot of warbirds from WWII used

[OR75]

This is what has been working for me :

If I know it will be a hot start , I will make sure the spark plugs are “cleaned “ when shutting down 

Hot start: full throttle , mixture full lean then crank , full reach and throttle back when the engine starts then lean 

if it does not start , it mean that it is not that hot of a start so go to a normal cold start (throttle cracked open, full rich, boost pump then crank )

[ZuluZulu]

20 minutes ago, OR75 said:

This is what has been working for me :

If I know it will be a hot start , I will make sure the spark plugs are “cleaned “ when shutting down 

Hot start: full throttle , mixture full lean then crank , full reach and throttle back when the engine starts then lean 

if it does not start , it mean that it is not that hot of a start so go to a normal cold start (throttle cracked open, full rich, boost pump then crank )

FULL throttle?  Your poor brakes!

[ZuluZulu]

5 hours ago, LeRoy Johnston said:

Great discussion--My mechanic (who owned an M20J for years), deliberately floods it so every warm start is a flooded start.  The idea is to start from a known condition.   We tried that too and it worked for me the first time but not the next day.   It's a little sporty because you need to be ready to back off the throttle.   Because it is not starting 100 percent reliably, we are going to do a complete ignition service--overhaul mags (at 500 hours they are due now anyway), new plugs with fine wires on the bottom, and of course set timing and check engine controls.  We know it's getting air and fuel, so this may be the answer.   I have learned a lot about the system from reading these posts, for which I am indebted to you all.  --LeRoy 

My mechanic and two IO-360 Mooney-owning CFI friends talked me out of fine wires -- just doesn't make sense on this engine, in their view.  They said the massives work just fine and there isn't enough of a performance difference to justify the increased cost of fine wires.  After putting 200 hours on my plane post-purchase, I've had zero spark plug issues other than replacing at annual on condition.  The old ones spent 403 hours in service after being installed during major overhaul.  And not all of them needed it but I elected to replace the entire set together for a little more $.  YMMV

Definitely overhaul the mags at 500 hours though.  My two CFI friends swear by it; never had a problem with their mags.

[N201MKTurbo]

1 minute ago, ZuluZulu said:

My mechanic and two IO-360 Mooney-owning CFI friends talked me out of fine wires -- just doesn't make sense on this engine, in their view.  They said the massives work just fine and there isn't enough of a difference to justify the increased cost of fine wires.  After putting 200 hours on my plane post-purchase, I've had zero spark plug issues other than replacing at annual on condition.  The old ones spent 403 hours in service.

Definitely overhaul the mags at 500 hours though.  My two CFI friends swear by it; never had a problem with their mags.

I agree completely. I have probably had 10 sets of spark plugs in my life. About 1/3 were fine wires. I can nurse a set of massive as long as a set of fine wires. I have noticed zero difference in performance. It either fires the charge or it doesn’t. 
 

People who buy fine wires have to brag about them because they have to justify how much they spent on them. It is just like premium gas For your car, it doesn’t do a damn thing for you unless you are racing, but people spend a lot on a car and feel that the car deserves it.

[OR75]

1 hour ago, ZuluZulu said:

FULL throttle?  Your poor brakes!

yes, full open throttle

and throttle back before you get any traction (mixture go up as throttle is brought back)

  

[toto]

1 hour ago, OR75 said:

This is what has been working for me :

If I know it will be a hot start , I will make sure the spark plugs are “cleaned “ when shutting down 

Hot start: full throttle , mixture full lean then crank , full reach and throttle back when the engine starts then lean 

if it does not start , it mean that it is not that hot of a start so go to a normal cold start (throttle cracked open, full rich, boost pump then crank )

That sounds like a standard flooded start procedure. 

[toto]

53 minutes ago, N201MKTurbo said:

People who buy fine wires have to brag about them because they have to justify how much they spent on them.

I had a lot of trouble with massives fouling on the ground, and I always lean as aggressively as possible. I switched to fine wires and haven’t had a single failed run-up due to a fouled plug since then. 

Whether I could have switched to the BY plugs or done something else, I don’t know. But in my case, the fine wires have been awesome. And I’m a card-carrying CB. 

[Ragsf15e]

6 hours ago, LeRoy Johnston said:

Great discussion--My mechanic (who owned an M20J for years), deliberately floods it so every warm start is a flooded start.  The idea is to start from a known condition.   We tried that too and it worked for me the first time but not the next day.   It's a little sporty because you need to be ready to back off the throttle.   Because it is not starting 100 percent reliably, we are going to do a complete ignition service--overhaul mags (at 500 hours they are due now anyway), new plugs with fine wires on the bottom, and of course set timing and check engine controls.  We know it's getting air and fuel, so this may be the answer.   I have learned a lot about the system from reading these posts, for which I am indebted to you all.  --LeRoy 

I would be careful with this.  It’s not exactly wrong, but you will eventually get the hang of a hot start with the mixture in cutoff.  When that doesn’t work, then flood it and start that way.

Theres a bit higher chance of a tailpipe fire when you flood it.  Done right, there’s a lot of extra fuel.  There are one or two folks on MS who’ve had it happen.  
I’d say I get a good start ~95% of the time on the first try.  Very rarely I will have to flood it.  Occasionally if it’s been 3-4 hours so it’s warm, ill try a hot start, if that doesn’t work, normal prime start, if that fails, flood it.  I almost never get to the flood start.

Last, once you flood it, you’re committed, but If you try a hot start first, you can still flood it and try that next.  Can’t go the other way though.

[carusoam]

Welcome aboard LeRoy!

You are going to find a few start techniques that work for you…. Take good notes.

When you get each one to work… you are going to to want to reference your notes…

 

1) regular start technique…

2) cold start technique…  

3) Hot start technique…

4) Flooded start technique…

5) Recognize when to use which procedure…

 

When you get a chance to fly with other people…. Watch their procedures…

Trying to learn these from written words will add to the challenge…

The DMax video above is classic…. Don is a procedures guy.  Follow the procedure, make the known adjustments to the procedure… obtain the success…

Look forwards to having all of these opportunities… you will get to see them all over your first year…

Listen to your engine… after a hot shut-down… you may even hear the fuel boiling in the fuel lines… you know when your engine is talking to you a hot start is probably coming up next…  

Go MS!

Best regards,

-a-

[EricJ]

1 hour ago, toto said:

I had a lot of trouble with massives fouling on the ground, and I always lean as aggressively as possible. I switched to fine wires and haven’t had a single failed run-up due to a fouled plug since then. 

Whether I could have switched to the BY plugs or done something else, I don’t know. But in my case, the fine wires have been awesome. And I’m a card-carrying CB. 

Same here.   My fouling problems stopped instantly when I switched to fine wires in the bottom plugs.   Tops are still massives.    Haven't tried the BY but wouldn't be opposed to them. 

[carusoam]

Focus on the procedures first…

Work on that whole repeatability thing…

 

Then add the hardware…

This is where spending OPM becomes really easy…

Did you know…

1) Electronic mags are the way to ease the starting process?

2) They improve start ignition timing…

3) They deliver stronger spark voltage…

4) Fine wires improve air/fuel flow in the area of the spark… big open gap…

5) That other device mentioned is good… but it was an improvement for the old technology…

6) None of this technology is required… The more you know, the less technology you will WANT to buy…

7) Some people want to by the technology anyways…   

PP thoughts only…

best regards,

-a-

[jaylw314]

2 hours ago, EricJ said:

Same here.   My fouling problems stopped instantly when I switched to fine wires in the bottom plugs.   Tops are still massives.    Haven't tried the BY but wouldn't be opposed to them. 

I gotta say, since I've started leaning aggressively during taxi 4-5 years ago, I've stopped seeing ANY lead fouling.  I swapped the bottom plugs for fine wires, and at annual both are squeaky clean.  During runups, I haven't seen any evidence of plug fouling on the engine monitor on either plugs.

When I first got the Mooney, I didn't lean aggressively and I'd get plug fouling on the runup every 3-4 flights.  Running the motor for 20 seconds before shutdown cut it down to every 8-10 flights.  Leaning aggressively got it down to zero.

In retrospect, the fine wires don't seem to perform any differently.  My mechanic thinks it's a mixed bag--he doesn't have to worry about gapping them, but he has to worry more about accidentally dropping them.   Cost wise, they're about 3x as much and theoretically can last 3x as long, so there at least a reasonable option.

[ArtVandelay]

Your fuel flow at 1000 RPMs should be 1.5gph or less, if it’s higher you’re running too rich,

[carusoam]

Jay,

accidentally dropping spark plugs… doesn’t matter regarding their construction…

Each dropped spark plug gets dropped a second time…. Into the trash can…

They hide their internal damage pretty well, neither can handle being dropped…

PP thoughts only, not a mechanic…. Let me know if this is an OWT.   

Best regards,

-a-

[A64Pilot]

12 hours ago, ZuluZulu said:

FULL throttle?  Your poor brakes!

No you catch it way before engine RPM goes very high, it’s not hard to keep RPM below 1,000, if your diligent, I’d never allow an engine to go very high prior to oil flow being established so if you couldn’t control RPM this way, I wouldn’t do it.

Being as it’s full lean it doesn’t rev fast, it’s a sort of stumble start, the mixture keeps it from revving up so as it starts snatch the throttle back and add mixture quickly.

‘The purpose of full throttle is believe it or not but it’s actually flooded and the full throttle allows as much air in as is as possible to clear the flooding

‘We have all heard that sizzling sound right after shutdown. that’s fuel dripping from the injectors, likely because the fuel in the lines is being boiled and pushes out any liquid fuel that’s left into the cylinder as it’s the only open end and that floods it.

Continental’s of course run their injector lines under the cylinder so as they are below the heat they aren’t nearly so bad about vaporizing the fuel in the lines.

 

I really hate calling it a “hot start” most of my time is with turbines, and I’ve thankfully never had a hot start, but just hearing the name gives me the willies 

Edited September 22, 2021 by A64Pilot

[Ragsf15e]

3 hours ago, carusoam said:

Jay,

accidentally dropping spark plugs… doesn’t matter regarding their construction…

Each dropped spark plug gets dropped a second time…. Into the trash can…

They hide their internal damage pretty well, neither can handle being dropped…

PP thoughts only, not a mechanic…. Let me know if this is an OWT.   

Best regards,

-a-

I think he just meant that he worries more about dropping the fine wires because they are 3x expensive ($120 ea?!), not because massives don’t break when dropped.

Edited September 22, 2021 by Ragsf15e

[PT20J]

According to Champion, the advantage of fine wires for avoiding fouling and better LOP operation comes from the electrodes being more exposed. The BY extended electrode plugs are supposed to provide the same advantages and were developed to solve lead fouling problems (In the C-152, if I recall correctly).

The other advantages of fine wires are longer life and lower maintenance since the electrodes don’t wear as fast. The longer life may be offset by the increased cost.

There are lots of anecdotal reports of people being pleased with fine wires over massive electrode plugs, but I’ve yet to find anyone who has compared fine wires to extended electrode plugs.

Skip

[RobertGary1]

WHat starter do you have? Haven’t found hot starts to be an issue since installing a high speed starter 10 years ago. 

[RobertGary1]

4 minutes ago, PT20J said:

According to Champion, the advantage of fine wires for avoiding fouling and better LOP operation comes from the electrodes being more exposed. The BY extended electrode plugs are supposed to provide the same advantages and were developed to solve lead fouling problems (In the C-152, if I recall correctly).

The other advantages of fine wires are longer life and lower maintenance since the electrodes don’t wear as fast. The longer life may be offset by the increased cost.

There are lots of anecdotal reports of people being pleased with fine wires over massive electrode plugs, but I’ve yet to find anyone who has compared fine wires to extended electrode plugs.

Skip

Fine wires really help on the bottom when you have an oil burner and they sit in oil overnight. 

[Ragsf15e]

Certainly anecdotal, but I have Tempest fine wires installed by the previous owner, 8 years and 750 hours ago.  Knock on wood, I’ve never had to put any thought into spark plug issues during that time.

[A64Pilot]

Hot starts can be very much of a plug issue, I sat for hours in my Maule trying to start it in Tuktoyoktuk NWT, and there were no maintenance facilities, plugs were carbon fouled and once I got it going and back to Inuvik I got them cleaned and no more issues.

[A64Pilot]

52 minutes ago, RobertGary1 said:

Fine wires really help on the bottom when you have an oil burner and they sit in oil overnight. 

It’s like most things, they are actually better, but only you can decide if they are worth the increase cost, of course an airplane can work just fine with massives, just as it can without an engine monitor, been doing so forever.

[RobertGary1]

18 minutes ago, A64Pilot said:

It’s like most things, they are actually better, but only you can decide if they are worth the increase cost, of course an airplane can work just fine with massives, just as it can without an engine monitor, been doing so forever.

Since I got my new engine that has been true.  But my old oil burner was very difficult to start on massives. 

[Shadrach]

I currently and always have run massive (sometimes longer than I should). The factory Bendix/SOS system in conjunction with massive plugs is perfectly adequate when the engine is hot or cold. If it’s not functioning properly or is mishandled, it gives what it gets… prime when cold. If not cold turn the starter and enrich the mixture when it starts. No need to slam the mixture forward nor is there a need to take several seconds. This is not worth overthinking.  If the the engine was shut down in the last 2hrs, it’s preprimed. Even if it was only run for 2 minutes…still preprimed.

I taxied to the wash rack to flush out my left fuel cell yesterday. The engine was run for less than 5 min with no cowl. Between the flushing and the BSing with other airport bums the plane had been sitting for over an hour. My hot start “procedure” was to turn the key and supply fuel when it started (2 to 3 blades), that’s it.  

My ignition system is in good working order. That run to the wash rack was the first time it’s been started in 13 weeks. Cold, it fired on first blade like a Gallows balsa wood model with a rubber band. I think starting problems are often maintenance related. Switch, plug, vibrator or failing retard breaker problems will almost be worse when starting a hot engine.

Edited September 22, 2021 by Shadrach