I flew my plane home from a very expensive annual (corrosion found starting under the floor, entire floor had to be removed) yesterday.

<200 hr Pponk, MT 2 blade prop, Sky-tec starter.

When I went to fire it up it turned over a couple times then just... stopped. It felt like a hard stop so I immediately turned it off and shut the master off. I thought about it for a minute and decided to get out and see it the prop would turn by hand. It turned forward and backward without any hesitation so I figured I might have experienced a kickback (per Motoadve's long thread) so I gave it another try to see if the starter would work. It turned a few times and fired normally. I taxied over to the fuel dock, added fuel, and it started again without incident.

Today I went to go for a flight and it turned over once then definitely hit a hard stop. I shut down and got out and it would not pull through by hand. I called my mechanic and he asked if it would pull backwards. It would go about 1/8 turn, then stop again. The prop was in exactly the worst position to use the tow bar so I tried wiggling it a bit in both directions and lo and behold, it pulled through at least half a turn before it stopped again. My mechanic asked me to remove the starter and it came off cleanly with no apparent damage to the starter. The prop would not turn freely at this point, just half a turn before hitting a stop that required a bit of jiggling before I could get another half turn. He asked if I could see the adapter gear turning when I turned the prop and it was not turning.

At that point he said it seems to be the starter adapter and told me to put the cowling back on and he would come take a look this afternoon or Monday. I'm looking for some advice and knowledge so I can ask good questions.

If it is the starter adapter, is that potentially catastrophic? In Motoadve's thread there was some talk about starter pieces floating around in the engine.

Again, if the starter adapter, does that require pulling the engine? I'm tied down outside and do not have access to a heater hangar and the mechanic is a couple hours away. Not an ideal setup for a visiting mechanic.

Any shared knowledge appreciated.

New or old style adapter?

By the way, if you have a new style, I believe that you do not want to attempt to manually turn your propeller backwards or the starter spring will tighten and then break, which is why a kickback event will leave you with a broken spring. If you have an old style adapter, you will be able to turn your propeller backwards.

I recommend signing up with Savvy for problems such as this. I use them and have been very satisfied with their assistance. My impression is that I get sound advice from a team of experienced mechanics.

Feel your pain, been there twice.
What breaks inside its the spring.
Remove the starter adapter, look at the spring, if you see its a clean break and you put it together and both parts fit , means there are no missing parts and no problem no need to open the engine or nothing.
Broke 2 starter adapters, both times it was a clean break.

On the second time went to buy a heavy duty starter adapter, this one took a kickback like nothing!
With a heavy duty starter adapter it would not break if you get a kickback, this could be enough to solve this problem.
I went a step further and went to a shower of sparks by Aircraft Magneto Service, smoother and easier starts than ever and no more kickback.

Thanks for the quick replies.

I think it would be the new style adapter as absolutely everything on this engine was new a couple years ago.

I don't think I'm dealing with either a kickback or a broken spring. If the spring broke wouldn't the engine turn by hand freely? And it was more of a hard stop than a kick back. The prop never rotated backwards until I pulled it by hand. It just stopped turning.

To tell what adapter you have the classic style with old type starter or skytec st3 prop can be turned back and forth. With new style adapter with these starters prop turns forward but not backwards. I have 180 with pponk with new style adapter and skytec st5 starter it turns both ways because starter disingauges starter drive with selinoid . Met a fellow in Alaska with a 185. Put a 3 blade mt on new style adapter first one lasted 5 hrs and broke 2 adapter lasted about 25 hrs broke then went to classic style adapter. Don’t know what starter but old style heavy with good battery best.

I'm going to make another plug for Savvy.

Now for the free advice. It never really sounded like a spring problem. I suggested originally, as an aside, that you shouldn't try to turn your motor backwards if you have a new style adapter because that will lead to a broken spring.

Since I have broken a spring with a new style adapter, this is what it is like:
Engage starter. Propeller starts to turn. There's a bang and a sort of whirring sound and propeller stops. Attempt a restart. Engage starter. There's a whirring sound and propeller doesn't move. Found a broken spring and a faulty magneto that led to a faulty timing event.

Broken spring or not, your motor won't turn freely by hand unless you remove the compression from all your cylinders.

Sorry to hear of your trouble, these things are one of the items that can get ugly on a Continental. Back in my younger days I worked for a shop (Aircraft Specialties Services) and one of my jobs was rebuilding these things. New or old style the principle is the same, a spring grabs a drum on the shaft that rotates against a gear on the crankshaft to start the engine. The older styles had a steel collar that was pressed into the aluminum housing which would drag the spring when energized by the starter, this would then cause the spring to collapse and grab the shaft, causing it to turn. As mentioned before, this unit when un-energized will not contact the shaft, allowing rotation in either direction. The newer style spring is a much thinner and responsive unit that is basically a drag fit on the shaft drum only and operates as a one way clutch. So if it is working correctly it will not allow reverse rotation. Impulse coupling/timing trouble is usually what causes the damage to these units and it can be severe. No matter which style you have, I have seen damaged springs so entangled around the shaft that it will not allow rotation at all. I have also seen partially collapsed springs that have nearly cut the shaft in two which is another nightmare thing to worry about. I also found later as an A&P a starter adapter on a TU206G which had apparently kicked back at some point, breaking a tooth off of the starter adapter gear and was left floating around in the sump. Thankfully for the pilot, he had heard a slight “ticking” on the ground (I never could hear it) and we had the unit, crank gear and labor taken care of by the overhaul shop(it was under warranty). You might contact A.S.S. and see if they have a rebuilt exchange unit (they used to in my day) that can help you get airborne sooner. Also have your mechanic look over the crank gear and it might be worthwhile to have it magnafluxed as a failure at that gear is catastrophic. Sorry for the long post and best of luck.

Great post by Idahowilly. You can pull adaptor without removing engine. Just takes some finess and swearing as you need to get the studs out, not just the nuts. Not a job you want to do outside if it's windy and cold.

Dozen's of threads and articles on adaptors on the net. Consensus mainly pushes to old style adaptor with a energizer or tempest old style heavy starter. Consensus changes a bit with lightweight MT props - leans a bit towards lightweight fast spinning starters - But you NEED to use a new style adaptor with these geared starters. The old style adaptors need to turn starter backward to disengage the spring - lightweight geared starters don't turn backwards - so a lightweight geared starter on an old adaptor is a recipe for failure.

In the sense of economy (loose term in aviation), I would pull the adaptor off myself - work slowly on some nice days and inspect - many pics on internet showing what to look for - If you find no issues beside the adaptor - order adaptor.

If you don't want to take this on yourself, order up a rebuilt adaptor from Niagra and have it there ready to go for your mechanic as well as a new starter if you decide to use an old style adaptor.

I don't think your going to find anything major but the adaptor from the sounds of it. Even if you do, your still going to need an adaptor. With the plane outside in the elements and you wanting to use it, having a mechanic drive 4 hrs round trip to pull an adaptor and then order one makes little sense - plus you have a big hole left open to try to seal from the elements while you wait two weeks for parts.

https://niagaraairparts.com/wp-content/ ... SB16-6.pdf

https://niagaraairparts.com/wp-content/ ... -sides.pdf

https://niagaraairparts.com/wp-content/ ... r-2016.pdf

Mark Y. wrote:…... Dozen's of threads and articles on adaptors on the net. Consensus mainly pushes to old style adaptor with a energizer or tempest old style heavy starter. Consensus changes a bit with lightweight MT props - leans a bit towards lightweight fast spinning starters - But you NEED to use a new style adaptor with these geared starters. ….

I disagree. My takeaway from all the web discussions is that due to the lack of mass & resulting lack of inertia,
the lightweight props (MT, for example) are more prone to kicking back than the usual metal props,
which being heavier tend to rotate right on through a backfire or kickback..
So they need the old adapter & heavy energizer starter even more than legacy props.
They are also more vulnerable if the timing is mis-set as to cause kickback.

I can see that for sure. Makes sense. One school of thought was the lack of weight for inertia needed a faster crank speed to make up for it and hopefully cause less chance of kickback. Really I see no practical reason to want to use the new style with a lightweight starter in any application.

Ditto Hotrod, putting the springs side by side you would see that the newer style unit is built almost like a slinky, and the older style spring coils are about 2-3 times as thick. With the older units you can use a high torque starter if you want faster speeds, but you must make sure it is one that can easily rotate when not engaged. This is also true for the older style starters. When we were first building our replacement springs we machined a adapter housing to observe the worm gear on engine start, it must reverse rotation about 2-3 revolutions if I remember correctly to allow the spring to relax. Any sludge from oil deposits, poor starter bearings, some magnet starters, etc. affect this and will cause premature wear of the spring and shaft. I would recommend anyone to have their mechanic pull the starter every annual or so to make sure it is in good condition and that the shaft can move easily as it is fairly simple to do and provides some insurance that the adapter will last. In addition I personally prime and pull the engine through (I know it is dangerous, but so is driving to the hanger) which helps the engine pretty much fire instantly keeping the load on the adapter at a minimum. In my opinion 500-hr magneto inspections, magneto to engine timing checks, good batteries that are fully charged, pre-heating and priming to reduce excessive cranking, and periodic inspection of the starter will help get the best life out of the unit, no matter which style adapter/starter/propeller combination you choose to use.

None of the new high torque starters turn backwards. They are geared and not direct driven. Old style adaptor should have a starter that takes no more than 5 in/lbs to rotate it backwards. Easily should turn by grabbing the shaft with pinched fingers. Wouldn't hand propping to prime to start increase your chance of a kickback? I think it would, especially if mag timing wasn't exactly optimal. Plus the main load on the adaptor is the initial start to crank - once cranking it is minimal. If anything I would start to spin the engine without turning mags on to get some momentum going before turning them back on.

That's what I do. After a kickback and adaptor failure with the MT prop and the lightweight starter, I bought the Hartzell Energizer starter and had the starter button reinstalled to be able to crank up to speed before turning on the mags. Everything has worked fine so far!

Again, the symptoms I'm trying to describe do not support my original hypothesis of either kickback OR adapter failure, unless there is more to the adapter than a spring that grabs the crankshaft.

If the spring was broke I would be able to turn the prop by hand without any issue but when I try and turn the prop by hand I hit a hard stop, as if something is stopping the crank from spinning, then if I play with it a bit I can pull it through about 1/2 a turn until the same thing happens again.

Mechanic coming Monday, I'll report his findings.

Spring breaks/distorts/jams up causing a huge drag. Running in this condition will chew the adaptor up and fill the engine with metal contamination. Only other cause for your symptoms would be a spun main bearing - I sure hope it's the adaptor for your sake.

Is kickback caused by BTDC timing at crank?

If so, is there an impulse magneto solution for these engines?

CamTom12 wrote:Is kickback caused by BTDC timing at crank?

If so, is there an impulse magneto solution for these engines?

The shower of sparks tied to a set of retard points of a magneto is very effective for starting and reducing kickback. Many cessna 100 series with a continental came stock with this setup. I don’t think it would be a major modification to add this ignition system to an airplane equipped with impulse mags. Besides, impulse mags kinda suck.

Surefly mags are said to improve starting significantly. My sense is that they may obsolete the shower of sparks mod for starting ease and reduced starter adapter failure. Opinions?

Pinecone wrote:Surefly mags are said to improve starting significantly. My sense is that they may obsolete the shower of sparks mod for starting ease and reduced starter adapter failure. Opinions?

If you have the odyssey firewall forward battery - they don’t meet the power requirements for surefly stc.

My pmags fire at TDC during cranking. I’m pretty sure the surefly operate the same way.

Can’t get kickback that way.