Starter Adapter now, new airplane is snakebit!

[MikeOH]

9 minutes ago, Ragsf15e said:

Oh, did you see the final verdict above? I posted it about the same time you posted about the battery. Starters aren’t cheap either. In fact, they’re about twice as much as a battery. Thank God there was one sitting on the shelf here though!

Ah, no I did not see your post!  Well, congratulations, .... I guess. As they say, why do airplanes fly...MONEY!

[Z W]

Good time to pickup a spare starter solenoid for the hangar shelf. I had a trip canceled by one going out, resulting in a similar experience. My prop even moved a little bit when I turned the key.

Starter solenoid:

https://www.aircraftspruce.com/catalog/eppages/sts-12s24s.php?clickkey=8060

Master solenoid:

https://www.aircraftspruce.com/catalog/eppages/skytec07-03565.php?clickkey=8060

Glad you got it figured out.

[Ragsf15e]

I was apparently hasty in saying it was solved or I jinxed myself.  Here’s what happened trying our next trip.  Apparently @kortopates trick to check the SA isn’t infallible (no blame intended).  Our starter didn’t seem right and the SA seemed ok.  This video is on the new starter though…

https://photos.app.goo.gl/5etj5CVeoEaSCJwQ9

We will check the battery before pulling it.

[kortopates]

So sorry you are still having problems.
So is your video showing zero prop movement?
What do you hear?
Sure it’s still not the starter? We should see prop move a bit till it slips, or at least hear it slipping?


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[MikeOH]

40 minutes ago, Ragsf15e said:

I was apparently hasty in saying it was solved or I jinxed myself.  Here’s what happened trying our next trip.  Apparently @kortopates trick to check the SA isn’t infallible (no blame intended).  Our starter didn’t seem right and the SA seemed ok.  This video is on the new starter though…

https://photos.app.goo.gl/5etj5CVeoEaSCJwQ9

We will check the battery before pulling it.

Check the grounds! (Especially, battery negative to airframe ground)

[Ragsf15e]

1 hour ago, kortopates said:

So sorry you are still having problems.
So is your video showing zero prop movement?
What do you hear?
Sure it’s still not the starter? We should see prop move a bit till it slips, or at least hear it slipping?


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The prop just twitches as I let off the key.  The starter itself is brand new (OH) out of the box.

Yes, the prop doesn’t move at all while the starter buzzes away, then barely twitches as I let off the key.  Weird.

To add to the story, I tried it about 3 times and was pretty quick between the last two (right after the prop twitches) and it caught, turned over and started (it starts very easily).  I really don’t know what’s going on?

[Aerodon]

You've checked about everything else, with the rear mounted battery there could be a lot of problems along the way:

1) Battery positive and ground terminals, Contactor (master solenoid) at rear.

2) Starter solenoid - its on the firewall in front of the circuit breaker panel.

3) Starter cable from solenoid to starter

4) Engine ground cable.

With a 28V system, the wire size generally isn't a problem, but I would still look for bad crimps, half broken terminals, washers in place, nuts torques etc.

 

Aerodon

 

 

[Ragsf15e]

20 minutes ago, Aerodon said:

You've checked about everything else, with the rear mounted battery there could be a lot of problems along the way:

1) Battery positive and ground terminals, Contactor (master solenoid) at rear.

2) Starter solenoid - its on the firewall in front of the circuit breaker panel.

3) Starter cable from solenoid to starter

4) Engine ground cable.

With a 28V system, the wire size generally isn't a problem, but I would still look for bad crimps, half broken terminals, washers in place, nuts torques etc.

 

Aerodon

 

 

Im definitely interested in helping my mechanic troubleshoot this to make sure we actually “fix” the right part this time… I will check the battery ground, but how would I check that the battery and starter solenoid are delivering full power to the starter with minimal resistance?  Check resistance at each step like in the skytech troubleshooting guide? 

[EricJ]

If your A&P (or somebody) is bold enough, put a multimeter across the hot terminal at the starter and nearby ground.   See what the voltage does during a start attempt.   If it drops to very low voltage, there is a problem somewhere between the battery and the starter.   That could be a loose or dirty connection, crappy relay, etc., etc.    Do the same at the battery during an attempted start.  If it drops just as much (or nearly as much) there during a start attempt, then it's the battery.

 

[Ragsf15e]

Just now, EricJ said:

If your A&P (or somebody) is bold enough, put a multimeter across the hot terminal at the starter and nearby ground.   See what the voltage does during a start attempt.   If it drops to very low voltage, there is a problem somewhere between the battery and the starter.   That could be a loose or dirty connection, crappy relay, etc., etc.    Do the same at the battery during an attempted start.  If it drops just as much (or nearly as much) there during a start attempt, then it's the battery.

 

Thanks, I appreciate that.  I think he’ll go for that.  

[Aerodon]

When batteries get old, they lose the ability to provide the current required for starting.  A new battery might start 10 times in a row without recharging, and old one might have worked last time and just doesn't work this time.

Can you borrow a battery?  Or try a battery cart at the FBO?

 

[Ragsf15e]

13 minutes ago, Aerodon said:

When batteries get old, they lose the ability to provide the current required for starting.  A new battery might start 10 times in a row without recharging, and old one might have worked last time and just doesn't work this time.

Can you borrow a battery?  Or try a battery cart at the FBO?

 

Yes, I was planning on using a start cart as a test as well.  I looked it up and the battery (Concorde) is 3 years old.  Passed cap check last month.  I will check out the electrical thoroughly before we attack the SA with tools.

[Z W]

+1 on checking the wires and solenoids.

Your starter solenoid is on the firewall above the co-pilot's feet. When a solenoid fails, it can do strange things like make a poor or partial connection and buzz, or only connect after you've turned the key several times. OEM versions of these have been unobtainable for a while. Some A&P's have been replacing them with $15 tractor solenoids from NAPA auto parts, which is apparently arguably legal under some interpretation, and is what I found installed on my plane. I much prefer the Lamar FAA-PMA solenoids from Spruce I linked above. The difference in quality is obvious when you compare them.

You can see most of the rest of the electrical starting system by opening the tailcone access door and it's right in front of you. The main ground terminal comes right off the battery and bolts to the avionics shelf in front of it. Check for corrosion between the wire terminal and the shelf. Spray some corrosion-x on it before you bolt it back on. Any wires that are corroded, or with cracked or discolored insulation, should be replaced with proper milspec wire, with ends properly crimped on using a hydraulic crimper like this one:

https://www.harborfreight.com/hydraulic-wire-crimping-tool-64044.html

I believe the above should be done at least every decade or so on any plane. If you don't know when yours was last inspected, I'd start there. It's an hour or two of inspection and good preventative maintenance. 

These types of threads usually start a contest of people posting how many years they get out of their batteries, with some of them pushing 7-8 years. That's all well and good, but in the interest of not canceling trips after I've got my plane loaded up to go, and not finding out my capacity is low after an alternator failure while flying IMC, I replace my battery every 3-5 years at the first sign of decreased starting performance. If you pay attention you can often tell when a battery is starting to get a little weak, as long as you keep your connections clean.

Hope you'll let us know once you get it figured out what the problem was.

[LANCECASPER]

The starter adapter will slip for a little while before it fails. My money is still on the starter adapter. 

[Ragsf15e]

On 6/1/2025 at 7:22 PM, EricJ said:

If your A&P (or somebody) is bold enough, put a multimeter across the hot terminal at the starter and nearby ground.   See what the voltage does during a start attempt.   If it drops to very low voltage, there is a problem somewhere between the battery and the starter.   That could be a loose or dirty connection, crappy relay, etc., etc.    Do the same at the battery during an attempted start.  If it drops just as much (or nearly as much) there during a start attempt, then it's the battery.

 

Did this today using the skytec troubleshooting guide posted earlier.  The electrical system passed.  The battery has ocv ~25.5.  While cranking the starter, battery terminal voltage drops to 22.5v.  Voltage at the starter was ~20.  All of that meets the skytec guidelines. We’re pulling the starter adapter later this week.

[Ragsf15e]

On 6/2/2025 at 6:25 AM, LANCECASPER said:

The starter adapter will slip for a little while before it fails. My money is still on the starter adapter. 

After testing the electrical system and the new starter motor, I believe you are correct.

[LANCECASPER]

6 minutes ago, Ragsf15e said:

After testing the electrical system and the new starter motor, I believe you are correct.

G & N did a great job on mine for a lot less than money than other companies wanted

 

[Ragsf15e]

53 minutes ago, LANCECASPER said:

G & N did a great job on mine for a lot less than money than other companies wanted

 

Thanks, Ive got a call in to them.

[Ragsf15e]

well here's another interesting saga... what exactly is the part number of the SA on a 252?  From the overhaul documentation 2 years ago, it says part #641348-a12.  If I look it up on Continental's IPC, it shows 653074A47 so maybe they've been superceded?  Well my IA called Niagra and they said they can't get parts for the original version anymore and don't have exchanges?  Heck mine was OH just 2 years ago, now no parts?  To make it more confusing, Hartzell and Skytec have PMA SAs with their own part numbers (55304 for Hartzell).

I just want someone to repair mine.  I'm waiting on a call back from G & N.

@kortopates @Z W @shawnd  Any ideas on the original part number and have you heard about no parts to repair?

[Z W]

@Ragsf15e Here's my last logbook entry on the starter adapter, from December of 2014:

I'm not sure if that's a G or a 6 in the P/N. Hope that gives you some more info. Might try Aircraft Accessories of Oklahoma.

[cbarry]

The other question that hasn’t been asked but needs to be answered is why the SA failed after only 200 hrs since overhaul (assuming it’s the failed component)?  Is there an obstruction in the oil galley feeding the SA causing premature wear?  Was the overhauled unit’s components (such as the cranking shaft) just at the minimum tolerance but still passed to be used again in the overhaul?

[Ragsf15e]

3 hours ago, Z W said:

@Ragsf15e Here's my last logbook entry on the starter adapter, from December of 2014:

I'm not sure if that's a G or a 6 in the P/N. Hope that gives you some more info. Might try Aircraft Accessories of Oklahoma.

Thanks!  Same part # as mine except mine is A12.  I might call continental today and see if they can help with 

[LANCECASPER]

27 minutes ago, Ragsf15e said:

Thanks!  Same part # as mine except mine is A12.  I might call continental today and see if they can help with 

You might even try a call to Don Maxwell to see what they are using on M20K 252s

[shawnd]

@Ragsf15e Looks like I had one OH’ed at Western Skyways. Here’s the part number:

 

[shawnd]

Though I think they may have the wrong part number listed in the 8130. They inspected, repaired and sent mine back.