Frustrating Starting Problem

[bucko]

I have a 1965 M20-E that just finished an extensive annual (most expensive ever) that found and fixed a great many things.  The plane is running superbly, but the problem is an intermittent starting dilemma.

 

IO-360 with a Sky Tech high speed starter that is approximately 8 years old.  Prior to the annual (finished in March), we got a new Gill battery.  (Don't want to have a battery discussion here, just giving background).

 

Starting issue was, and has been for a while, very episodic, meaning NOT Easily Reproducible.  Get in, do the normal pre-start sequence per the POH) and most of the time it would fire right up.  Then, would start having troubles.  The, would start without problem.

 

Today:

Turn key, press in as key all the way over to right, hear buzzing (Shower of sparks), hear the starter relay click, and then NOTHING.  No prop turn.  No fire.

 

Release key: Buzzing stops. Hear the click of the starter relay repositioning. 

 

Retry without success.

 

In the past, I've had success in turning everything off, exiting the plane, rotating the prop to a new position, getting back into the plane, and going through the start sequence.  Most times that works like a charm.  No idea why, but it does. (Note: Prop always stops in the same position. Not sure if it's the same blade, but always in the 2-7 position- looking from the pilot seat.)

 

At the recent annual, a new ignition was placed along with a new starter relay.  Worked great for about 10 starts (enough to get the plane home), but now is acting up again.

 

Today, my partner flew the plane about an hour doing IFR approaches.  Plane started right up for him.

2 hours later, I pulled the plane out of the hanger and tried multiple starts: NOTHING.  Move the prop.  NOTHING.  2 other Mooney pilots try.  NOTHING.  Multiple attempts.  Hook up to outside power (maybe not enough volts, but greater than 13 plus volts on the JP)I:    NOTHING.

 

I guess all that is left to replace is the starter.  

 

I know the mechanic is going to pull the plane out tomorrow and it will probably fire on the first blade.

 

We cannot seem to find any loose connections.  And we never seem to be able to reproduce the problem when the mechanic is there with his testing equipment.

 

Any thoughts would be appreciated.

 

Bucko

[bonal]

So last few flights I was having starting issues, cold first starts were perfect then when engine was hot or even semi hot I would get nothing. I was thinking solenoid but others including my mech said its your bendix sticking. All other things were fine so I thought spraying silicon into starter as recommended would be easiest to try. After doing so I have made several hot starts without any problems. Give that a try cause it's easy and cheap

[Browncbr1]

I had this on a truck once. The bendix grease was dried out with dust and sticky. You could hear the starter spinning free without engaging the flywheel.

[jamesm]

Could it be an intermittent Ignition / cigar lighter Curcuit Beaker  (they don't pop it is an internal to the CB)?

Several years ago this  problem bit me being that was an intermittent Circuit breaker and only thing else on circuit was the cigar lighter which often time can be an intermittent connection in it self.

Also check wire terminations/crimps terminiations can  start to break over the years and act like intermittent.

[Marauder]

Usually it is the Bendix not moving forward to engage but there is usually a whirling noise of the starter spinning and the Bendix not engaging. If it is the Bendix, I have this happen on the first start of the day and then sometimes on a hot start.

Silicone was the preferred lubricant since it wouldn't leave a petroleum residue when the solvents evaporated. It worked for a bit, but last year it was not helping and I got stranded one day at the gas pumps.

I had used Deep Creep by Seafoam on a few things around the house. Since I was headed for a starter replacement, I gave it a try. One application and no more issues. Just be careful you don't get it on the alternator belt.

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[Yetti]

If the starter does not spin it is not the bendix. Unless the bendix is sticking engaged.  Silicone it.   I would suggest one phase of the starter armature is bad.   When it stops on the bad part, then it won't spin off.  or the brushes are broken

[M20F]

I would reccomend the next time it doesn't start running jumper cables directly to the starter from the battery. If it engages than you know it is something backward in the chain causing the problem (i.e. the starter isn't the issue). If it doesn't engage and you are hooking up correctly it is the starter, try hitting a couple times with a rubber hammer and see if it starts. This will often unstick the Bendix. Obviously be careful not to kill yourself attempting this.

[N201MKTurbo]

If you are creative you can get a new bendix from the NAPA. It needs a slight modification, but it will work and it costs about 15 bucks.

[tony]

I had a problem similar to what you describe and it ended up being a bad ground from the tray to the airframe.  Removing the avionics tray revealed that both the tray and the airframe were painted.  Cleaning up the bonds. cured the problem. 

 

Take a volt meter and see if there is a voltage drop between the negative lead of the battery and the airframe while someone tries to crank it. 

[Nemesis]

First off, I could be wrong, but as I remember SkyTec starters do not have a conventional Bendix. They employ a different method to engage / disengage.

The first things that I would search for would be crimp connectors and/or dirty corroded connections.

If a crimp connector gets corroded, that corrosion can hide under the connector and inside the wire's insulator cover.

If that happens, it can certainly give an intermittent connection which can vary with temperature.

I know it is a huge pain in the ass, but I would probably disconnect the battery, and starting at the starter high-voltage connections, remove, clean, and inspect each connection all the way back to the battery. By inspect, I mean to grab very firmly and try to twist and flex the crimp portion of the connector and the first couple of inches of wire to see if any green corroded copper falls out. I hate to suggest all of that work in that I would hate to do that myself or pay to have it done for me.

See you in Kerrville in a couple of weeks.

 

Dave

[Guest]

There is a trouble shooting flow chart on the Sky Tec web site, with it you should be able to locate your troubles.

Clarence

[neilpilot]

When my Skytec failed, I had similar intermittent failed starts.  Sent the starter back to Skytec, and it was a bad starter.  No Bendix in a Skytec starter.

[capthaak]

I am having exactly the same issue on my 81 J. Brand new Sky-Tec. Just got it out of annual too.

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[capthaak]

If you are creative you can get a new bendix from the NAPA. It needs a slight modification, but it will work and it costs about 15 bucks.

Don't even think about this.

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[flyingvee201]

When I first got my M20F, I had the same issue. It turned out I made a rookie mistake.

My ignition switch SAYS to PUSH in and TURN the ignition key to START.

I still make this mistake once in a while "thinking" im pushing the key in when I guess its not enough. nothing happens....prop wont turn...nothing.

 

Try that.   next time....as you are turning the key....make SURE you are pushing it in as well.  :-)

[jamesm]

I have often wondered  if the correct model of Sky-tec starter are being  installed on Lycoming engines  for the 180/200  HP  Mooneys .   I have the 149-NL for my '67 C. If I recall correctly all Mooney are suppose to have either 149/122 NL sereies according to Sky-Tec's fit guide (the NL series  sort resembles  the old bendix starter minus the housing).  However I have seen  various other SkyTec models   like  HT / PM installed on other Mooney's.  I have also told that early model  Skytec issues like in 1990's but I hear Sky-Tec are very good about supporting their product.

James

[carusoam]

FV brings up a good point...

The ignition switch doesn't last 50 years. I think my C got 45 years and 5,000 hours out of it.

It gets temperamental at first, then it stops working altogether. First, finding the right position and the right pressure to work the magic. Then the magic was gone...

If it is the original switch, it is pretty easy to swap out.

Best regards,

-a-

[N201MKTurbo]

There are two kinds of Sky Tec starters one has a solenoid off to the side which engages the bendix and has the contractors to send current to the motor. The other kind just has the motor and an inertial bendix. The one with the solenoid off the side is a Denso starter used on quite a few Toyoyas with a modified mount. The hanger faries had to change a ring terminal to make the standard solenoid work. Besides if the starter doesn't work the plane is very safe, if you can't start the engine you can't fly and crash.

http://www.ebay.com/itm/BWD-Starter-Solenoid-S5613-/161393129676

[Xinder]

Did you ever find out what was the problem I have a m20e also with the same problem let me know.

[jghyde]

On 7/28/2024 at 9:09 AM, Xinder said:

Did you ever find out what was the problem I have a m20e also with the same problem let me know.

I had this problem. Changed out everything from the key (switch) to the starter. Turned out, it was a 3-yr old weak battery. I'd say the chances are 75% that's what it is!