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Starting troubles, need tutorial


Amelia

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My Screaming Eagle has had spells of being hard to start. Now it doesn’t start at all. Both 24v batteries check out fine. First attempt to start resulted in a few turns, a cough, and nothing. Second attempt resulted in a brief grunt, about 3 inches of prop turn. Switch battery,  same grunt and no cranking. The nearest mechanic, good guy, but not a Mooney guy,  is 40 truck minutes away. And I’m stuck here in the back of Beyond. Any ideas how troubleshooting might begin, once he gets some time for a road trip?

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Something that might help...

The typical problem I have had starting my IO550 on a cold day...

Stems from fear of over priming...

The result, is under priming...

So let’s begin with priming...

Do you...

  • push the mixture in all the way?
  • push the throttle in all the way? (Required for proper amount of fuel flow)
  • use the proper seconds of prime using the High boost.  Based on outside air temp..
  • Allow some time for evaporation.

 

  • Really important....  pull the throttle back out
  • 1.5 turns of the throttle (target to get 1,000 rpm)
  • expect to need the low fuel pump to be running when you start the engine.
  • It will probably run lean and then die if the low boost isn’t running...

Does this sound familiar?

I wrote this from memory, I can get my checklist if you’d like.

On the other hand... I’m not sure if you said your batteries are able to turn the prop?  That would be different than the priming discussion I wrote about above...

If you are waiting for somebody to arrive, can you start charging the batteries? In case this is helpful...

Good luck,

-a-

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Thanks! I will try those things (again) tomorrow, in the hope we aren't talking about starters and other expensive things. Should be briefly a good bit warmer, too.

and I really do intend to figure out how to make an avatar again, if such nostalgia is unseemly. :D

 

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For the avatar...

One and done...

Its like a finger print.  You are recognized by the pic you used...

Most avatar pics are put up quickly, before anyone realizes how long they are going to stay...

If you do change it, include you co-pilot in the photo... :)

 

Other details from my check list...

>40°F is the temp for a regular start... prime 5-10 secs with High boost...  (higher number when it’s colder)

<40°F recommends low boost on for start...

 

Good luck and Best regards,

-a-

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If you follow the AFM procedure your Eagle should start very easily, always on the first attempt. At least mine does.

Whats really tricky in our aircraft is a hot start. After trying many different things I have settled on ensuring the engine is at 1000 RPM on shutdown, then starting without touching the throttle and without priming (so just mixture rich), when the engine catches, keep it running with flicks of low boost. Have your right hand on the low boost switchen when you turn the key.

 

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The cheapest problem would be discharged batteries.  Even a cheap 15 A charger should get you enough juice in a couple hours of charging, you don't need to get the batteries to 100% to start the engine normally.  On the other hand, if the batteries are weak, you might need to, and it might help to move the prop to a different position by hand before you start--a weak battery might be able to crank it through one of the compression areas if it has some space to build up momentum.

 

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Sure fire way to know its the starter adapter is if the starter "whirres" and the prop has a very delayed movement or moves a bit then stops. If the starter and starter adapter are all in proper working order, then my limited experience is, my Ovation takes low boost for 10 -15 seconds, then I wait for about 1 minute letting fuel vaporize. after the 1 minute or so I engage the starter with throttle position screwed in about 5 or 6 twists, and as soon as it hits I turn on the low boost and leave it on until I hear the engine start to load up just a bit then off with it but keeping my finger ready in case it starts to need an additional squirt which is the case in cold weather. I have been flying an Acclaim for about a month and it seems to want more fuel when cold. It likes high boost for about 10 seconds, set throttle about an inch in, engage starter, soon as it hits the low boost goes on and stays on until the engine warms up. It will get to the point to where it starts to load up a bit and then the low boost must be turned off and momentarily tapped. by the time the engine is warm enough for take off it doesn't need and more low boost help. It is due an annual very soon which at that time SID 97 is going to be done just to make sure fuel system is set up properly.

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I celebrated this beautiful 65-degree sunshine by hauling the Mooney out of its hangar, noted that the lightbulb perched under the cowling had warmed the underpinnings nicely, the south-facing translucent hangar doors had the hangar in the mid70s. Battery voltages well in the green.

No excuses, right?

Followed starting instructions to the letter. First crank produced a hopeful bit of enthusiasm, then died. Second and third attempts merely a grunt. Same on battery number two. 

Guess it’s time to start replacing fancy stuff. Sigh.

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If it’s whirring but the prop isn’t turning it’s likely the starter adapter. If the starter stalls out and can’t turn the prop it could be the starter motor.  If neither maybe the batteries.  

Note about those starter adapters. George perry had an eagle and put a brand of starter adapter and it failed right away and he was 3-4 grand into it before getting it done right. Seems there’s only one kind that’s any good, iirc it’s the one that’s new,  it rebuilt, and uses the big heavy (durable) motor. 

Update.  Here’s the thread. Seems iskra and skytec won’t do the job and trash the starter adapter and energizer is all good. 

 

Edited by jetdriven
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1 hour ago, Amelia said:

I celebrated this beautiful 65-degree sunshine by hauling the Mooney out of its hangar, noted that the lightbulb perched under the cowling had warmed the underpinnings nicely, the south-facing translucent hangar doors had the hangar in the mid70s. Battery voltages well in the green.

No excuses, right?

Followed starting instructions to the letter. First crank produced a hopeful bit of enthusiasm, then died. Second and third attempts merely a grunt. Same on battery number two. 

Guess it’s time to start replacing fancy stuff. Sigh.

Keep in mind, an unloaded, but bad battery could be in the green.  Try checking the voltage with some known loads.  Pitot heat is always a good one as well as some lights.  If it drops out of green rapidly, it still could be batteries?  How old are they, when did they last fly and when were they last checked.  Of course it could be any of the other things folks have mentioned.  

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It’s called a battery capacity test and it’s in the Concorde battery service manual.  Anyways you put a specified amp draw on the battery until it gets to a specified cutoff voltage of 20v. Then put the minutes into the formula and it gives total capacity. Iirc they want 90% capacity to be airworthy. 

5-0171.pdf

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5 hours ago, takair said:

Keep in mind, an unloaded, but bad battery could be in the green.  Try checking the voltage with some known loads.  Pitot heat is always a good one as well as some lights.  If it drops out of green rapidly, it still could be batteries?  How old are they, when did they last fly and when were they last checked.  Of course it could be any of the other things folks have mentioned.  

And if they're Gil's, check the electrolyte levels?

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13 hours ago, Amelia said:

I celebrated this beautiful 65-degree sunshine by hauling the Mooney out of its hangar, noted that the lightbulb perched under the cowling had warmed the underpinnings nicely, the south-facing translucent hangar doors had the hangar in the mid70s. Battery voltages well in the green.

No excuses, right?

Followed starting instructions to the letter. First crank produced a hopeful bit of enthusiasm, then died. Second and third attempts merely a grunt. Same on battery number two. 

Guess it’s time to start replacing fancy stuff. Sigh.

Do you mean that the propeller wouldn’t turn at all, or that the blades quiver along with a whirring sound from the starter and won’t go through a compression stroke?

Battery type, Gill or Concord makes a big difference.

Starter motor type, Iskra, Sky Tec, Hartzell, TCM energizer, and best of all Tempest.  

The best starters and batteries will save your starter adapter which is worth more than the others combined.

Clarence

 

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Mimi, you've had several helpful suggestions from Clarence and others more knowledgeable than I am... I would think task one would be to be sure those batteries are strong. If they're Gills and several years old they are suspect. If they're Concordes and only a few years old I would be wondering if the alternator and the voltage regulator are maintaining a good charge. In my 12V system that's ~13.9V in cruise but your 24V system might be about 26V but that should be verified. Remember too that a cold battery will deliver much less power than a warm one. That would not explain the problem you still had when the weather had warmed up but when it's cold enough to do a preheat remember that the batteries are in the tailcone.

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Thank you to all who have offered good suggestions. I looked through the logbooks, and at least one of the batteries is a two-year old Concord. I believe they both are, but need to look closer. No idea what brand the other things are, but will soon, maybe tomorrow, have a cowling off and an expert at my elbow, to point these items out. I hooked up a new battery-minder, and an hour later, it indicated a full charge. I might go see if that fixed the problem. Hope springs eternal. In any event, I’ll be reading these thoughts to my friend the mechanic at my earliest opportunity. 

Again, many thanks, all of you. 

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Taking bets...?

  • Battery charge level... remember Batteryminders are best when they match the brand and type of battery...
  • Battery failure.... Concorde vs. Gill
  • Starter Solenoid... responsible for delivering the amps required to move the prop... they can age and not deliver the amps...
  • Starter motor... OEM starters haven’t had a lot of complaints.  There have been a few...
  • Starter adapter... a friction clutch device that may have difficulty with some oil additives... (George outlined this one)
  • Ignition switch... sends power to a Solenoid...
  • Battery terminal and all the electrical connections up to the starter....oxidation can inhibit electron flow.
  • got any white salty looking build-up on the battery terminals or rich green looking surfaces on connections?

Quick question...

What happens to the voltage reading when the starter is engaged?

Funny thing...

I can’t push the button to read volts when starting my plane.  Quirky old Mooney challenge.  Volt and amp meter is the same device. To read volts the pilot has to push and hold the button.... I have only two hands...

Sounds to me...

  • Batteries are charged
  • some electricity is getting to the starter
  • but not enough to develop the proper torque to push the prop through the compression stroke...
  • if this is the case, the Solenoid and all connections are suspect, or the starter is weak...?

Be extra careful being anywhere near the prop..

PP thoughts only, not a mechanic...

Best regards,

-a-

 

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11 hours ago, Amelia said:

Thank you to all who have offered good suggestions. I looked through the logbooks, and at least one of the batteries is a two-year old Concord. I believe they both are, but need to look closer. No idea what brand the other things are, but will soon, maybe tomorrow, have a cowling off and an expert at my elbow, to point these items out. I hooked up a new battery-minder, and an hour later, it indicated a full charge. I might go see if that fixed the problem. Hope springs eternal. In any event, I’ll be reading these thoughts to my friend the mechanic at my earliest opportunity. 

Again, many thanks, all of you. 

The two-year old Concord should be OK unless both batteries were really abused.  Most battery minders will measure the state-of-charge as a percentage, but there's a big difference between 100% of a good battery and 100% of a bad battery.  The only way to tell the difference is to do the load tests previously described (or test the battery in a different plane).

 

10 hours ago, carusoam said:

What happens to the voltage reading when the starter is engaged?

Funny thing...

I can’t push the button to read volts when starting my plane.  Quirky old Mooney challenge.  Volt and amp meter is the same device. To read volts the pilot has to push and hold the button.... I have only two hands...

With the amount of amps going to the starter, the voltage can drop extraordinary amounts even during normal starting, well below 12v/24v.  It's hard to draw any conclusions from that, though.

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Hallelujah! I don’t even mind feeling stupid... A couple of days on the trickle charger, a nice warm light under the nosewheel well, and it finally, after a good bit of coaxing, started with a satisfying rumble this afternoon. So another bit of education. Just because it thinks it’s charged, doesn’t mean it is.  . Warmed up the oil, and took myself for a sunset ride around Edenton.Way too long between flights. I’m glad my dear 20-year old CFI friend was along to keep things in the proper order.

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