Sky-tec failure

[KCKS]

Has anyone identified the specific starter defect that is causing problems?

I've looked all over and found nothing.

[Dan L]

I replaced the starter on my O-340 this spring. It lasted about 1100 hours. It lost its ability to spin strongly and would hang up on a compression stroke. I suspected a weak battery at first but it was the starter.

[Andy]

I replaced the starter on my O-340 this spring. It lasted about 1100 hours. It lost its ability to spin strongly and would hang up on a compression stroke. I suspected a weak battery at first but it was the starter.

What starter model number was that and did you open the defective one to find out what was wrong with it?

[Dan L]

A 149 12HT H.

I did not take it apart. It had a $200 core value.

[Bill Tew]

After ~ 350 hrs. on my EX-2, the engine starter has started to misbehave. Every now and then, I can hear the solenoid click but the prop does not move. Can occur on first start up out of the hangar or anytime after a flight. Fortunately, when it happens away from my home field, I've been able to hand prop for start. Happened again yesterday after a short flight to West Desert, UT - hung around there for ~ an hour and upon restart attempt prop wouldn't turn. After returning to KHCR and shutdown, it restarted just fine. Currently it's working but this intermittent problem is keeping me close to home. Eck!!!

Battery is good. Will replace solenoid just in case but can't fully diagnose issue until it fails again which seems to mostly happen when away from my home field.

Has anyone had a similar starter issue and solved it?

Bill

[Andy]

If it were mine I'd take it apart and find out what was wrong with it. I don't know what the price of parts is like but replacement of the starter is not inexpensive.

Maintenance manual here - https://skytec.aero/wp-content/uploa...5-Rev.-New.pdf

Rambling discussion but no definitive diagnosis here - https://www.supercub.org/forum/threa...tarters.58881/

Some internal pictures of an HT here - https://jdfinley.com/sky-tec-starter-overhaul/

[Andy]

Every now and then, I can hear the solenoid click but the prop does not move.

Unlike the older "Bendix" style these light weight starters engage the drive pinion with an electrical solenoid. I don't think the starter motor is energized until the mechanical solenoid has extended.

When it fails next can you see if the pinion is being extended by the solenoid? It may take a remote camera to view this safely.

I was not able to find an overhaul or service manual. Hartzell seems to have them locked up in a paid subscription site.

[Pete D]

After ~ 350 hrs. on my EX-2, the engine starter has started to misbehave. Every now and then, I can hear the solenoid click but the prop does not move. Can occur on first start up out of the hangar or anytime after a flight. Fortunately, when it happens away from my home field, I've been able to hand prop for start. Happened again yesterday after a short flight to West Desert, UT - hung around there for ~ an hour and upon restart attempt prop wouldn't turn. After returning to KHCR and shutdown, it restarted just fine. Currently it's working but this intermittent problem is keeping me close to home. Eck!!!

Battery is good. Will replace solenoid just in case but can't fully diagnose issue until it fails again which seems to mostly happen when away from my home field.

Has anyone had a similar starter issue and solved it?

Bill

Bill, you might reach out to SkyTech/Hartzell on this before you try opening it up. They were working on a change for the solenoid on the starter for an issue that sounded like this and may now have a field kit.

https://skytec.aero/aircraft-starter-support/warranty/

[Bill Tew]

Spoke with a tech rep at Hartzell - the starter supplied with my Carbon Cub EX-2 engine is not serviceable. If the battery's good and the starter solenoid is sending correct voltage to starter - then it's time for a new one. Current replacement model through Cub Crafters is SRZ-9021-1.

At the moment everything is working fine. Hopefully, the starter gremlins will wake up soon and I can confirm the problem.

Bill

[Andy]

They were working on a change for the solenoid on the starter for an issue that sounded like this and may now have a field kit.

There are reports that the solenoid can be replaced by a Ford part as fitted to late model Crown Victoria. Fit would likely depend of the specific starter model. My FX-3 uses Lycoming part number 31A22104 which I think is equivalent to Sky-Tec 149-12LS.


Over $1,000 to replace the starter and about $20 for a solenoid. Seems to be worth a try if the solenoid is suspect.

https://vansairforce.net/threads/sky...lenoid.135453/

https://www.amazon.com/Replacement-F.../dp/B06XXS3LGV

Some people are carrying a spare Ford solenoid just in case they have to do a field repair.