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M20E has gotten hard to start/won’t start...


N9405V

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Hmmm...

1) Hot starts are terrible... they can leave you stranded when you run out of batteries....

2) Turbines start with no difficulties...their hot start is a different problem after the engine is running sort of...

3) I need to convince my finance administrator the Mooney for her has a turbine engine....

 

I’m just thinking way out of the box, and way down the road... :)

 

Best regards,

-a-

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My issue has nothing to do with starting procedure. After doing more trouble shooting today it looks like the sos is beyond its service life and a new one has been ordered. We’ll see if that’s it.


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On 9/11/2018 at 7:31 PM, carusoam said:

Hmmm...

1) Hot starts are terrible... they can leave you stranded when you run out of batteries....

2) Turbines start with no difficulties...their hot start is a different problem after the engine is running sort of...

3) I need to convince my finance administrator the Mooney for her has a turbine engine....

 

I’m just thinking way out of the box, and way down the road... :)

 

Best regards,

-a-

I USED to have this problem with hot starts. I had around 3 to maybe 4 good tries then the battery would fail and I would need a jump. I wanted to be able to go places that a jump was not available and be confident I could get off the ground. I bought a slick start magneto booster and it completely removed any starting problem I ever had. Cold, hot, too rich, it didn't matter, my airplane now starts on the first or second try every time. I have no connection to this product whatsoever, but I think it was one of the best gadgets I bought for less than a grand, highly recommended if anyone has any starting issues without an actual engine problem.

https://www.aircraftspruce.com/catalog/eppages/slickstart.php?clickkey=6866

Sure, I did get pretty good at doing hot starts eventually, but now, I've experimented with all sorts of things, leaving the mixture full, using DM's technique, half mixture, doesn't matter. Almost every combination except for leaving the mixture completely out starts every time on 1 or 2 tries. Almost too easy.

 

JB

 

 

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1 hour ago, JohnB said:

I USED to have this problem with hot starts. I had around 3 to maybe 4 good tries then the battery would fail and I would need a jump.

Good Lord, I know this is OT, but when I had a bad magneto, I was probably cranking for 10-15 tries (about 15 seconds each), and the battery was still going okay (definitely better than my nerves).  Failing after 3-4 tries suggested a not-so-good battery...

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My E has always starts hot (including Texas hot) or cold and I've rescued more than one pilot that I've seen burning out his starter by showing him the correct way to hot start...It is very, very frustrating for the pilot when they cannot start their hot io360.  Maybe a little helmet fire starts when she does not fire on the first few blades?

Interestingly the lycoming tio540-u2a has one technique for starting hot or cold, including prime first the, then idle cut off while cranking and then slowly enrich after start.  That works on the a1a as well.

mooney exterior.jpg

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8 hours ago, Badmoonraising said:

I have the same problem. Drives me crazy. If and when I sell this airplane that will be the reason. I've tried all sorts of different procedures. None seem to be consistent. 

In a few weeks we'll celebrate the 53rd birthday of my E. She has, in the 9 years that I have owned her, started flawlessly under all conditions.

I think you need to take yours to the E-whisperer. He did the annuals on mine for a decade before I bought her and because of that I did no pre-purchase inspection.

Hie thee to KGGG.

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19 hours ago, jaylw314 said:

Good Lord, I know this is OT, but when I had a bad magneto, I was probably cranking for 10-15 tries (about 15 seconds each), and the battery was still going okay (definitely better than my nerves).  Failing after 3-4 tries suggested a not-so-good battery...

Interesting Jay. I did note on a friends J, he had a ton more tries at starting that I ever would have. On my bird, the 5th try on one battery was definitely wimpier, and the 7th, fuhgeddaboutit! I wonder if there’s a model difference? Or it could be that I drained my battery from previous hot start attempts then jumps in my early Mooney flying time. Well that’s all gone now thanks to my slick start. And I don’t have to ever stress about being stuck somewhere particularly at airports where the only living thing around is a cow who probably won’t help you much. :) 

I love the sound of my engine running, as it means fly time... and the sounds during starting add tension in anticipation of the sound that will hopefully very soon come!

 

(Ok so I’m feeling poetic today)

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3 hours ago, JohnB said:

Interesting Jay. I did note on a friends J, he had a ton more tries at starting that I ever would have. On my bird, the 5th try on one battery was definitely wimpier, and the 7th, fuhgeddaboutit! I wonder if there’s a model difference? Or it could be that I drained my battery from previous hot start attempts then jumps in my early Mooney flying time. Well that’s all gone now thanks to my slick start. And I don’t have to ever stress about being stuck somewhere particularly at airports where the only living thing around is a cow who probably won’t help you much. :) 

I love the sound of my engine running, as it means fly time... and the sounds during starting add tension in anticipation of the sound that will hopefully very soon come!

 

(Ok so I’m feeling poetic today)

The J uses a 35 Amp hour battery, so in theory, if you're cranking at 200+ amps, you should be able to crank for about 6 total minutes before discharging your battery to 50% capacity.  Sure enough, after my extended cranking, when I hooked up the charger, it said I was down to about 60% capacity, which is in about the right ball park.

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Theory doesn’t cover a two year old Gill lead/acid battery...  one or two attempts are OK, third or fourth not going to happen in winter...

Even a Concorde will be draining if not used in a couple of weeks...

Use a battery tender...

Fun facts for batteries, MS style...

Best regards,

-a-

 

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6 minutes at 200 amps from a 35 amp-hour (measured at 1 hour discharge rate) lead acid battery?  

That’s 5.7 times  higher current than the 1 hour rate and is going to deplete even a brand new, fully charged  battery.   

6C6FCCB5-873A-4A5D-8ADB-9902B6A315B7.jpeg.7c1825f4b3e038eb4dd391a15b5d7550.jpeg

Note the time scale is logarithmic. The 5.7CA curve reaches 10 volts almost 10 times sooner than the 1 CA curve.  

Pulling the 6 cell battery below 10 volts is not recommended for battery health.  

(Of course that’s of academic interest only: I hear IO-360s always start right up.  GREEN FONT). 

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Mine started getting harder and harder to start. Finally got to the point of screw it, I didn't even want to mess with it or fly. My AP started a shotgun approach to try to fix the problem. It would crank and crank until flood and dripping fuel. Then it was just a typical badly flooded engine. I would go back the next day and try again. I was getting very discouraged. I might get lucky and it would catch and fire up, but was always a gamble and usually a 35-40% chance it might start. This went on for a week.

First he suggested a bad left mag..we replaced it. He said it was probably due for replacement anyway as it had been on for many years.. ( I didn't buy that, but he's the expert). So I bought and replaced left mag. Still not better.

Replaced the plugs, still not better.

Kept working my way down the line...many hours of research of the possible root of the problem and many hours of my own time checking wiring etc. P-Leads, looking for ignitions shorts etc.

Bottom line after checking everything possible with exception of SOS box,( it couldn't be that). It was showing all the systems of a properly working box. I've got the buzz, the spark etc..It must be good (Yeah right).

I finally caved and took the chance on the SOS and ordered a new one. Swapped them out, pulled out of the hanger and started on the 3rd swing. WOW..could this have been it. Shut it down and repeated 3-4 more times easily, again and again within just a few swings. Even hot starts improved.

I keep the old SOS little son of a bit@H box sitting on my workbench to remind me that even if something might look and sounds okay..It's still 50 years old and can fool you.

Nearly a year later and starts are a non-event, a few swings and the lion roars. I really think it starts better now than it ever.

-Tom

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5 hours ago, Jerry 5TJ said:

6 minutes at 200 amps from a 35 amp-hour (measured at 1 hour discharge rate) lead acid battery?  

That’s 5.7 times  higher current than the 1 hour rate and is going to deplete even a brand new, fully charged  battery.   

6C6FCCB5-873A-4A5D-8ADB-9902B6A315B7.jpeg.7c1825f4b3e038eb4dd391a15b5d7550.jpeg

Note the time scale is logarithmic. The 5.7CA curve reaches 10 volts almost 10 times sooner than the 1 CA curve.  

Pulling the 6 cell battery below 10 volts is not recommended for battery health.  

(Of course that’s of academic interest only: I hear IO-360s always start right up.  GREEN FONT). 

the 6 minutes is not continuous, it's intermittent, so there are rest periods which presumably make a difference.

Where did that diagram come from?  I have a hard time believing a 35 Ah lead acid battery is only good for 40 minutes at 50 W output.  heck, people used to park their car and leave their headlights on for a few hours without discharging the battery...

Edit: Looks the diagram is supposed to be for a 12v Panasonic VRLA computer backup battery up-vw1220p1.  Panasonic's data sheet does NOT list Ah capacity, but lists the capacity by time--"30 minutes -- 57 W; 15 minutes -- 91 W; 10 minutes -- 120 W".  So if you figure it's a 20 Wh battery (which the part number suggests), they've spec'd the battery to produce that output for 10 minutes.  I don't know if car or plane batteries are spec'd the same way.

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5 hours ago, jaylw314 said:

....Where did that diagram come from?  I have a hard time believing a 35 Ah lead acid battery is only good for 40 minutes at 50 W output.  heck, people used to park their car and leave their headlights on for a few hours without discharging the battery...

The chart is for a smaller lead acid battery and was supposed to illustrate the difference between the 1 hour rating at 1C and the much higher starting current discharge rate. It’s not a linear relationship.  

If a brand new 12V Gill or Concorde battery will source 35 amps for 60 minutes at or above 10 volts ( the stated capacity test) then will it crank at 200 amps for a total of 6 minutes?  That was the question & the answer is, yes, barely.  

10 volts x 200 amps is 2000 Watts.  That’s nearly 3 horsepower. Not bad for a small box filled with some lead and acid.    

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On 9/11/2018 at 10:31 PM, carusoam said:

.....Turbines start with no difficulties...their hot start is a different problem after the engine is running sort of....

“When you start your piston engine your troubles begin. 

Once you have started your turbine engine your troubles are over.”

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19 hours ago, Jerry 5TJ said:

The chart is for a smaller lead acid battery and was supposed to illustrate the difference between the 1 hour rating at 1C and the much higher starting current discharge rate. It’s not a linear relationship.  

If a brand new 12V Gill or Concorde battery will source 35 amps for 60 minutes at or above 10 volts ( the stated capacity test) then will it crank at 200 amps for a total of 6 minutes?  That was the question & the answer is, yes, barely.  

10 volts x 200 amps is 2000 Watts.  That’s nearly 3 horsepower. Not bad for a small box filled with some lead and acid.    

If my math is correct (always questionable), a 35 Ah 12V battery has enough juice to lift a fully loaded Mooney 300 feet in the air.  Yes, that's pretty good for a little box.

12V x 35 Ah = 420 Watt hours = 1,500,000 Joules

height = energy / (mass * g) = 1,500,000 J / (1500 kg * 10 m/s2) = 100 meters

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On ‎9‎/‎14‎/‎2018 at 12:21 PM, N9405V said:

Well, put in a new shower of sparks and presto, fired right up...


Sent from my iPhone using Tapatalk

Put that on your toolbox as a reminder...Old stuff might look and appear right, but it's still old. It took a shotgun approach of replacement parts and a few thousand dollars until I figured the problem out. Great thing about MS. Maybe the next guy will learn from our money and time spent. Mine sounded right (buzzed and the plane would start if it was in a good mood), by the end it was nearly always difficult. Still had some spark, just not enough to do the job. It was always kind of quirky to start, but I thought it was just mastering the hot start technique. Like I said,  after the new SOS it's a non-event and I never dread shutting down for fuel stops or whatever...always a pucker whether it would catch or not..just got worse over time. I wonder how many guys are flying and worried about hot starts when actually most of the problem is a weak or poor performing original SOS?.

Glad it worked out and your flying again.

-Tom

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