Engine won’t crank. Help stranded in Danville ,IL

[billy hellcat]

Need some expert Mooney advice. Just purchased a 68 m20c today! Flew it for for 4 hours before taking it home. Performed flawlessly.   On trip home stopped for gas .  Upon startup it didn’t catch.   Prop rotating just won’t start.  Hot start for sure.   On 3rd attempt prop just didn’t move.  I hear a clicking sound when I engage and depress the start switch. No prop turning.  The prop doesn’t move when I tried to move it with my hand.  Is the starter still engaged?  I am not sure what starter it is.  Battery is a year old and is a concorde.   Not sure of brand of the starter. 
Any advice would be appreciated to troubleshoot.   I have a mechanic coming in the morning but he doesn’t know much about mooneys.

[hammdo]

I had a starter relay in my 66 that needed replacing. Located on the firewall pilots side, would click when it got hot. Not sure if 68 has it on the same side…

this may be the pma one:

https://www.aircraftspruce.com/pages/el/relays/sts-12s24s.php

verify against the one installed. Also, may want to get electrical contact spray for the ignition switch to clean it also:

https://www.amazon.com/Hosa-D5S-6-DeoxIT-Contact-Cleaner/dp/B00006LVEU/ref=sr_1_6?crid=23D1S44W9NZZ6&keywords=Electrical+Contact+spray&qid=1689400201&sprefix=electrical+contact+spray%2Caps%2C155&sr=8-6

-Don

[Mooneymite]

Fuel, fire, or air...the trinity of engine starting.  The O-360 is not prone to hot starting issues.

If the prop turns, and you have fuel and air, I'd suspect the shower of sparks first.  Pretty easy to check.

[takair]

Maybe just hot start gone bad and battery dead. Let it cool and get a jump start. My guess I that will get you going. 

[billy hellcat]

prop won't move by hand 

 

[markgrue]

I am an hour south of you.   I can come up and take a look at it when the weather clears if you still need help. 

 

 

Mark 

[neilpilot]

5 minutes ago, billy hellcat said:

prop won't move by hand 

 

Check to be sure started bendix doesn’t remain extended and engaged to ring gear

[takair]

33 minutes ago, billy hellcat said:

prop won't move by hand 

 

Missed that part.  Even if the Bendix was engaged, it usually allows prop to turn, unless the starter has other issues.  As others suggested, look at the starter.  When facing the plane, it is at about the 4 or 5 o’clock position.  Is the small gear on the starter engaged to the big ring gear?  Harder to see if you have a cowl closure.

[A64Pilot]

I’m betting dead battery / loose or dirty main power wire and the bendix still engaged. I’m thinking the prop will turn just he isn’t applying enough force to turn it.

 

[Ragsf15e]

Can these get “hydro locked” when flooded and make it feel like the prop is hard to turn?  Maybe it turns fine in the morning?

[PT20J]

16 minutes ago, Ragsf15e said:

Can these get “hydro locked” when flooded and make it feel like the prop is hard to turn?  Maybe it turns fine in the morning?

That would take a lot of flooding as you'd have to fill a cylinder clearance volume.

Sometimes what happens in a hung start is the Bendix drive doesn't retract and this causes there to be a ratcheting sound when the prop is turned by hand. If the prop won't turn by hand at all, something mechanical is amiss and needs to be investigated. If the engine or starter were jammed in some way, however, I would expect the starter CB to pop rather than a clicking sound from the starter solenoid which usually indicates a very weak battery.

However, from the symptoms described, what likely happened is that the battery is old and weak and an unsuccessful hot start ran the battery down. Batteries sometimes recover enough to start if left a bit and it might start after the engine is cold and the battery has rested. Otherwise, use a start cart to get it going and replace the battery as soon as possible.

Skip

[chriscalandro]

Put a charger on it. Wait an hour for it to cool. Try again. 
 

the Bendix is still engaged. It will become unengaged when the engine starts - probably. 

[billy hellcat]

Alright took the cowling off so I could see what’s going on. No prop movement forward or back. Battery was good.   Looks like bendix teeth broken and jammed.  . What do you guys see? Its a delco remey starter.  Should I get a replacement bendix or replace the whole starter motor?   

[hammdo]

For that amount of work, a skytec may be in order - just a thought…

-Don

[PT20J]

Replace it with a Sky-Tec. Lighter weight and spins faster. Mine is a 149NL. 

[BigD]

I replaced my old starter on my 65 C a few years ago with a new skytec - I’ve been happy with it. I think it was 400 bucks at time. Probably more now. Check flywheel for missing teeth. Hopefully it’s ok.


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[A64Pilot]

I’d check timing too, make sure the mag(s) are operating properly in case it fired way early and that was from kick back.

[EricJ]

That's probably the best reason for a seized prop that I can think of. 

+1 on a Sky-Tec replacement.   It's a better starter and weighs less. 

Also, take a good look around the circumference of the ring gear to make sure that stray tooth came from the Bendix and not the ring gear.    This is just to make sure you're fixing the right thing.

The starter swap-out isn't trivial since a lot of stuff has to be moved out of the way, but isn't too awful.   Even if the mechanic isn't Mooney-expert, the starter swap is common to Lycomings.

[A64Pilot]

Before you replace that starter read this article, specifically the paragraph entitled kickback

https://www.aviationconsumer.com/uncategorized/starter-replacement-consider-weight-hot-starts/

It could be that your starter just broke for no reason, but sometimes when things break something else broke it, and if you don’t remedy the problem, the new part can be broken too, or other parts, like the ring gear.

[billy hellcat]

Is it the 122 or 149 teeth on a 1968 m20c?

[M20F-1968]

It should be the same as on my F model, but I do not remember the number.  I should be able to tell the number of teeth on my F from the starter madel and/or serial number.  I'll keep you advised.

John Breda

[billy hellcat]

thanks

 

[Jim Peace]

When I had my new sky tech starter put in they had to get a different power cable...or make the existing one longer...I forget....it's been years and so far so good...

[markgrue]

31 minutes ago, billy hellcat said:

Is it the 122 or 149 teeth on a 1968 m20c?

It could be either depending on the flywheel part number.   Best to  count them. 

 

Mark 

[kerry]

The teeth on the ring appear to be U shaped which would be 149. V shape has 122 teeth.  When I replaced my stater, I decided on B&C. I'm very happy with it.