Starting Issue?

[PierceM20F]

Hi all, recently I've noticed that my skytec starter doesn't engage to the starter ring right away (or so I think). I push the key and assembly in and turn clock wise against the spring (like I always have done for over a year) and I'll hear a buzzing noise for a split second or so, THEN the prop moves slightly, stop, then begin spinning like it normally does. When it spins like normal, I would consider it a strong spinning start. It's just that initial turn over. Once the prop gets spinning like normal, the engine starting is not an issue. Takes maybe 3-4 turns and it fires up. 

Basically, it seems like there isn't enough power to get the prop to start spinning, but then magically the power appears after a second or two of struggling. 

Condor battery from 2019. 

Any thoughts? Maybe I don't have an issue? Just different than normal. 

[ShuRugal]

26 minutes ago, PierceM20F said:

Hi all, recently I've noticed that my skytec starter doesn't engage to the starter ring right away (or so I think). I push the key and assembly in and turn clock wise against the spring (like I always have done for over a year) and I'll hear a buzzing noise for a split second or so, THEN the prop moves slightly, stop, then begin spinning like it normally does. When it spins like normal, I would consider it a strong spinning start. It's just that initial turn over. Once the prop gets spinning like normal, the engine starting is not an issue. Takes maybe 3-4 turns and it fires up. 

Basically, it seems like there isn't enough power to get the prop to start spinning, but then magically the power appears after a second or two of struggling. 

Condor battery from 2019. 

Any thoughts? Maybe I don't have an issue? Just different than normal. 

Can you take a video with clear sound?

 

It sounds to me like what you are describing is that you can hear the shower of sparks module before your ignition switch makes contact, but that shouldn't last four several seconds.

[PierceM20F]

That makes sense on the shower of sparks. The buzz only sound lasts for a half to 1 second or so until the prop starts spinning. Maybe it's my ignition switch? I'll grab a video next time I fly. 

[Ragsf15e]

40 minutes ago, PierceM20F said:

That makes sense on the shower of sparks. The buzz only sound lasts for a half to 1 second or so until the prop starts spinning. Maybe it's my ignition switch? I'll grab a video next time I fly. 

To expound on the shower of sparks, it starts when the key is turned to start (turned against the spring tension), the starter is not engaged until you push in the key.  There is usually a split second where the buzz is going before the prop turns.  

The “juice” has to activate the starter solenoid too, so there’s another place you could be having an issue…

[PierceM20F]

I’ve been pushing and twisting at the same time. Maybe it’s something as simple as needing to push in harder and then twist. 
 

I think the starter solenoid is easily accessed with the cowling off…

[markgrue]

You should be twisting first and then push. 

 

Mark 

[Vance Harral]

9 minutes ago, PierceM20F said:

Maybe it’s something as simple as needing to push in harder and then twist. 

Traditionally it's the other way around: twist first and verify the "buzz" of the SoS system.  Then push to engage the starter.  I didn't think you could push in without first twisting all the way clockwise.  If you're pushing first, then twisting, you may be using the ignition switch in a manner it's not design for, and that may be part of why you're getting odd behavior.

Also, be aware that the behavior where the vibrator engages via twist, and the starter engages upon push, is only true of "most" vintage Mooneys, not all of them.  If you look at the factory schematics for the last few years of the M20C/D/E/F, the "S" output of the ignition switch is wired directly to both the starter solenoid and the IN terminal of the SoS vibrator.  In these later models,  nothing at all happens until you both twist and push.  That's the way our 1976 M20F behaves.  I used to think something was wrong with the way it was wired, based on the way everyone describes this "twist first to engage the SoS, then push to engage the starter".  I finally realized it was designed differently right from the factory.

[PierceM20F]

Okay, before I go down a rabbit hole, I will go verify that it’s not ME that is the problem. Twist then push! Be back with updates in a few days. Thanks all. 

[PierceM20F]

Okay, I flew yesterday and made sure to twist first, then push in. I tried taking a video but of course the prop didn't act like what I described. Instead, something else happened. I had just landed to get gas and then start it up again. 

1. Twisted key

2. SOS started with the buzzing noise

3. I pushed in

4. After pushing in, something sounded like it was "charging up" and prop did not spin at all.

5. After maybe 1-2 seconds of this "charging up" noise, the prop was almost "jolted" (it wasn't violent) into a strong starting rotation. 

6. Of course it was a little finicky on getting started because engine was hot etc. BUT each time I tried starting it, I heard this "charging up" noise (not to be confused with the SOS buzzing) and the prop wouldn't rotating until that charge up noise was at its max or maybe some level of power was reached before engaging into the prop. 

Anyway, I got the engine started and after the charging noise, the rotation was very very strong. If you were watching from outside the plane, you would say there were zero issues with any starting at all. From the inside, I feel like maybe I've been operating the starting switch improperly all this time...assuming this charging up noise is normal. 

[Skyland]

There's a shear pin in the Skytec starter.  A while back mine sheared completely and the lay shaft would turn but not the gear.  Maybe yours is catching in a strange way.  Skytec conveniently supplies two extra shear pins silicone glued within the base plate of the starter.  They must figure you're going to need them someday.

https://skytec.aero/wp-content/uploads/2018/02/NL_Shear_Repair.pdf

[Ragsf15e]

1 hour ago, PierceM20F said:

Okay, I flew yesterday and made sure to twist first, then push in. I tried taking a video but of course the prop didn't act like what I described. Instead, something else happened. I had just landed to get gas and then start it up again. 

1. Twisted key

2. SOS started with the buzzing noise

3. I pushed in

4. After pushing in, something sounded like it was "charging up" and prop did not spin at all.

5. After maybe 1-2 seconds of this "charging up" noise, the prop was almost "jolted" (it wasn't violent) into a strong starting rotation. 

6. Of course it was a little finicky on getting started because engine was hot etc. BUT each time I tried starting it, I heard this "charging up" noise (not to be confused with the SOS buzzing) and the prop wouldn't rotating until that charge up noise was at its max or maybe some level of power was reached before engaging into the prop. 

Anyway, I got the engine started and after the charging noise, the rotation was very very strong. If you were watching from outside the plane, you would say there were zero issues with any starting at all. From the inside, I feel like maybe I've been operating the starting switch improperly all this time...assuming this charging up noise is normal. 

Someone smarter maybe has a better idea, but I’d be suspect of the starter solenoid.  When you turn, that solenoid should immediately connect the fat cable going to the starter with the battery and spin the prop.  On second thought, maybe that part is working and the starter isn’t immediately engaging teeth in the gear?
 

It would be useful to (very carefully!) stand near the pilot side of the engine with the cowl off and turn it over.  If the weird noise is coming from the front (starter area) or the firewall (solenoid) that might narrow it down.

[A64Pilot]

The “charging up” is likely the starter spinning, then the sudden jolt of the prop is likely the bendix becoming unstuck and engaging with the starter spinning.

‘I suspect a sticking bendix.

[PierceM20F]

I believe I have a solenoid actuated starter? Sorry, I’m still learning all of this as I go. I believe the solenoid is on the firewall there on the right side. Shiny silver color. Which I believe means I don’t have a Bendix drive? 
 

At the same time though, the charging up noise would make sense regarding the starter spinning and then finally engaging. Something must be sticking somewhere! 

[A64Pilot]

Most all starters have a solenoid that powers the starter,  or they have to have a really big switch to hold that kind of current.

But some starters have a solenoid on the starter itself that serves two functions, one is it jams the starter drive out to engage the flywheel and then provides current to run the motor.

Being that your starter solenoid is remote mounted I’m betting you have a bendix drive.

If it’s a sticking bendix, it’s not doing your flywheel ring gear any favors

[A64Pilot]

This may help

https://www.lycoming.com/content/how-clean-your-direct-drive-engine-starter

[Ragsf15e]

The solenoid is circled on the right.  Starter ring gear circled on the left (pretty close to the starter).  I would guess @A64Pilot is correct.

[PierceM20F]

Yup, I think this is what is going on. Hopefully this isn’t too big of a deal…I’ll be at the hangar tomorrow and begin to take a look at this. I’ll report back any findings. Thank you all! 

[Shadrach]

5 hours ago, Skyland said:

There's a shear pin in the Skytec starter.  A while back mine sheared completely and the lay shaft would turn but not the gear.  Maybe yours is catching in a strange way.  Skytec conveniently supplies two extra shear pins silicone glued within the base plate of the starter.  They must figure you're going to need them someday.

https://skytec.aero/wp-content/uploads/2018/02/NL_Shear_Repair.pdf

Mine did his. My starter was inconsistent in its performance for quite a while before I called Hartzell about the symptoms. They thought it was a voltage or a ground issue. I verified that neither was the issue. They asked me to remove and send in for inspection. They called a few days later to tell me the sheer pin was broken. I asked how the starter continued to function with a broken sheer pin. The tech said he didn’t know.

[MikeOH]

3 hours ago, Shadrach said:

They called a few days later to tell me the sheer pin was broken. I asked how the starter continued to function with a broken sheer pin. The tech said he didn’t know.

Complete SWAG:  Friction.  Whatever is spinning (motor shaft) is heating up and 'seizing' up due to friction with what should be turning (Bendix gear/mechanism)

[PierceM20F]

Okay this is what I’ve got. A sky tec. But I also took pics of the starter from what I can see. It does look quite dirty. I was reading on Mooney space someone else had similar issue and sprayed a dry lubricant silicone in this area. Thoughts? 

[A64Pilot]

I believe a Sky -Tec is a solenoid actuated starter, and doesn’t have a bendix, if that’s true then you have another animal, and the shrapnel pin may be worth checking

[EricJ]

That's a Sky-Tec, so you don't need to spray that one, since it doesn't have a Bendix.    As previously mentioned, there's a slight chance that the shear pin has been sheared, but removal of the starter is required to check that, so I'd rule out a lazy starter relay or other easier things, first.   Might be worth checking that the wire cable connections are clean, too.

Usually if the shear pin is sheared it won't turn the prop at all, so that's still low on the likelihood scale.

 

[PierceM20F]

Okay all, so I called sky tec technical support and after about a half hour, we determined that this particular starter was experience a known design defect of some sorts causing it to not engage the ring gear. It was manufactured in 2009 and I guess that year/design does in fact have a Bendix. I honestly can’t describe exactly why it was failing but the tech rep knew exactly what it was and is having me exchange the unit. Something with loose bolts/nuts inside the unit.  
 

Let’s just say, removing the lower cowl was not a pleasant time but I got it done. Also, sky tec technical support is fantastic. Hopefully will be back flying by the end of the week. 

[Ragsf15e]

6 hours ago, PierceM20F said:

Okay all, so I called sky tec technical support and after about a half hour, we determined that this particular starter was experience a known design defect of some sorts causing it to not engage the ring gear. It was manufactured in 2009 and I guess that year/design does in fact have a Bendix. I honestly can’t describe exactly why it was failing but the tech rep knew exactly what it was and is having me exchange the unit. Something with loose bolts/nuts inside the unit.  
 

Let’s just say, removing the lower cowl was not a pleasant time but I got it done. Also, sky tec technical support is fantastic. Hopefully will be back flying by the end of the week. 

Be real care With the ram air “rubber” duct when messing with the bottom cowl.  Those are not available if you put a hole in it which is surprisingly easy.  They could be a grounding item depending on the creativity of your IA.

[PierceM20F]

Will do. I didn’t have too much trouble getting those bolts off. I have a plan for putting everything back together now that I know where everything is at.