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Hot, start, Click ???? Anyone else?

BillL

Well Known Member
Short version: flew - landed, sat 20 min, lack of starter engagement on restart. Click - -

Anyone else had this happen with the SkyTec LW starter?

Long Version background:
RV7 - SJ Cowl
YIO-360 M1B - stock - w/SkyTec LW starter
14 hours into PH I

Moderate OAT 45 F, flew 45 min made a good landing and decided take a water break. The plane sat with no wind for 30 min, then got to starting - just a click, 10 times ( maybe more, it was a lot) Click- clearly the start contactor on the firewall, but no other sounds. Finally, kept up the attempts and it engaged and spun and started. Until that, nothing but clicks. The voltage did not drop either.

The plan is to decowl and run some wires to test voltage:
1. to starter via large cable,
2. voltage to the start engage wire from the FW contractor.
In addition, place a thermocouple on the starter solenoid (for SkyTec techs)

Possible issues:

Bad FW Starter contactor - not passing voltage to starter
Hot starter solenoid - needing more voltage for pull in than available

I pull tested all the big terminals by hanging (me) from them. Book pull test is 525 lbs and granted I am only 150, but not loose. This only happens when it is hot, this is the second time for the click event.
 
Is it a single click and then nothing? I had an issue on my 172 where the skytec starter cracked which messed up the pinon alignment. The clicking I heard was the pinon slamming into the ring gear trying to engage. Replaced started and ring gear, no other issues.
 
I had this issue on my plane just a few hours into phase I as well. I have a YIO-360-M1B with a Skytec LW starter. I ran multiple tests to find the problem and concluded the solenoid was bad. It appears to be somewhat of a common problem from searching the forums. I called SkyTec and they were quick to have me ship it back to them, however, after they received it I was told it tested within their specifications on their bench. This greatly confused and frustrated me, but to their credit they did warrant the starter and sent me a new one after about a week long discussion. In hindsight I wish I had done more tests before I shipped the starter off. It looked like the solenoid was weak and would not engage unless the ring gear was aligned precisely with the pinion gear. I had installed the started exactly as Van's recommends. There has been much discussion about whether or not to remove the jumper that comes on the SkyTec starters. I think there is good reason to remove the jumper, and separate the wiring of the solenoid and the starter, but my theory is that the size of wire used for the solenoid is often not large enough to allow enough amps to flow to the solenoid causing it to lack the power it needs to engage. I have found that the initial current draw for the solenoid can be higher than one might think. I decided to wire the new starter with the jumper installed. I cannot say for sure what my original problem was, but SkyTec said there was nothing wrong with my starter and I have not had any issues with it since. Good luck and let us know what you find.
 
With the cowl off, you should be able to hear the difference between (among) a starter contactor (the thing on the firewall that looks similar to your master contactor), the actual starter *solenoid* (on the side of the starter).

Since some installs don't have a starter contactor (using instead, a heavy duty PB on instrument panel directly activates the starter solenoid, which completes the high current circuit on the starter), that may color what you hear.

Some starters use a lever controlled by the starter solenoid to move the pinion; some use a 'worm' gear to move it forward as the starter starts to spin.

If you hear a 'clack' but get no prop motion at all, odds are that either the contactor contacts or solenoid contacts are bad.

Don't forget that either a weak battery, or poor connection anywhere between the battery + & battery - terminals can give the same symptoms. If there's no voltage drop when you activate the starter, every connection, in addition to the contacts in the contactor and the solenoid, are suspects.
 
I went through the same issue with the same starter on my rocket last year. The starter had less than 200 hrs since overhaul. Replaced the solenoid no help. Replaced starter with a brand new NL starter no problems since.
I don?t pretend to know the inner workings of the starter but the old one for lack of a better term seemed to have a dead spot.
Ryan
 
The light weight skytec starters are hard on solenoids. You can take the starter to any automotive starter/alternator shop and they will have off the shelf parts to fix it. The only thing aviation about the starter is the casting, the rest is stock automative parts.

After a few years of this nonsense I replaced the unit with geared starter, I believe it might be KPS? This is a much better unit, does not spin the engine quite as fast but has been trouble free. Aside from the casting the electoral and geared portion are exactly like the unit that is on my 35 year old Toyota forklift. Again parts are off the shelf at auto shops.

I have heard good things about the longer inline starter; It just would not fit my installation as easily as the geared version.
 
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Starter

I have an AEIO-360 & C/S on my -4 and had a Skytec lightweight 149 on it. After 3 starters barely cranking and frying themselves I switched to a 149NL high torque starter with no issues since. No idea why the original builder put such a light starter on the airplane.
 
I had this issue on my plane just a few hours into phase I as well. I have a YIO-360-M1B with a Skytec LW starter. I ran multiple tests to find the problem and concluded the solenoid was bad. It appears to be somewhat of a common problem from searching the forums.
Thanks Bruce and Mark, since this only happens after a hot shut down and soak, and others have had the issue it seems a higher probability. I'll prepare an extra, larger gauge, wire for the solenoid, that is a good comment. And some old experience with VW 6 volt starters comes to play. I will also add grounding to my list, even though I have a solid case ground.

With the cowl off, you should be able to hear the difference between (among) a starter contactor (the thing on the firewall that looks similar to your master contactor), the actual starter *solenoid* (on the side of the starter).

Remember, I have had zero issues with all the starts when cool. If it were a gear lead relief issue it should have surfaced at least once when cool. The starter contactor is Vans standard, wired exactly like they recommend. Having tried it many times before success, I am pretty sure there was only the firewall solenoid clicking. But I will inspect the pinion face to be sure. I was reading the voltage in two places. One is directly connected to the master contactor, the other is off the buss internally on the Dynon D6. The Dynon read 12.4 volts. It stayed there when held in start position before and after the click.

Thanks for all the comments, I searched a couple of ways and did not find a low hour, hot only, solenoid issue. I am loathe to replace any parts on a stock, new, starter that is supplied by Lycoming to do this job. When it works, it always spins well and has never kicked back. Even after the click event, when engaged it spun a hot IO engine fast and it started/fired in a couple of blades. I am going to work with SkyTec technical staff to get data they are happy with. Hopefully, the parts can pass in the mail. Waiting a week is not good just when the weather is getting flyable.

I have thermocouples in a lot of places, so adding one to the solenoid is a non- issue. Too bad a DAQ unit is not owned to record them all simultaneously.

I'll keep you posted, Thanks Again VAF!!
 
starter

Bill, I have a new Skytec starter like you have on the shelf if it helps you get flying sooner. I am in Lena il. Not too far away. Ron 815 291 8864
 
I replaced the solenoid on my new Skytech 149-12LS after less than a year in service with the same issue as yours. Used Duralast SS1115 from Autozone to fix the problem. Cheap and simple to repair.
 
Final Resolution - -

A shout out for Hartzell/SkyTec support: ALLEN!! I had a test plan and he was quite receptive to stepping through it. He stopped me in the middle and said," Bill, we are going to get you fixed up even if it is a warranty starter"- - WOW.

We finished our discussion and I installed a wire to measure voltage to the starter solenoid actuation, to the high amperage side, and a thermocouple on the case. Oh - and a local ground just-in-case it was part of the problem. The solenoid temp runs about 160F all the time and 170-180F after shutdown if not forced cooled.

Drum roll . . the Vans firewall starter contactor was not making good contact and not supplying voltage to the starter. It was wired to the small post per Vans wiring diagram for these starters (but measured at the starter). Only happened when hot. A new contactor is on order from Vans. If any new information is discovered, I'll post it.

I really appreciated the offer of a starter from Ron. Thanks!!
 
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A shout out for Hartzell/SkyTec support: ALLEN!! I had a test plan and he was quite receptive to stepping through it. He stopped me in the middle and said," Bill, we are going to get you fixed up even if it is a warranty starter"- - WOW.

We finished our discussion and I installed a wire to measure voltage to the starter solenoid actuation, to the high amperage side, and a thermocouple on the case. Oh - and a local ground just-in-case it was part of the problem. The solenoid temp runs about 160F all the time and 170-180F after shutdown if not forced cooled.

Drum roll . . the Vans firewall starter contactor was not making good contact and not supplying voltage to the starter. It was wired to the small post per Vans wiring diagram for these starters (but measured at the starter). Only happened when hot. A new contactor is on order from Vans. If any new information is discovered, I'll post it.

I really appreciated the offer of a starter from Ron. Thanks!!

Hi Bill -
Can you do a quick autopsy of the solenoid? Drill out the four riverts. You should find the low current post is attached to a copper strap that rides on the high amperage disk to make the connection when the solenoid plunger is pulled in. You don?t need to use the Low current post. That is a hold over from the early light weight starters that could stay engaged if the on board starter solenoid was wired to the high current circuit.
If all looks good, something is really odd that heat would affect such a simple solenoid. Perhaps a bad connection in the coil to post?
Just curios.
 
Hi Bill -
Can you do a quick autopsy of the solenoid? Drill out the four riverts. You should find the low current post is attached to a copper strap that rides on the high amperage disk to make the connection when the solenoid plunger is pulled in. You don’t need to use the Low current post. That is a hold over from the early light weight starters that could stay engaged if the on board starter solenoid was wired to the high current circuit.
If all looks good, something is really odd that heat would affect such a simple solenoid. Perhaps a bad connection in the coil to post?
Just curios.

Absolutely Jon, the parts have not arrived yet, agree it's odd. I ordered a new one in case I get stuck off my home airport. (I could aways let it cool). I think I'll move that thermocouple to it and see what the heat soak is, and measure some voltages there too before it is removed. Then try to reproduce on the bench with a heat gun. Probably a waste of time, but will certainly take it apart and get some pictures. It only does this when hot, after a heat soak. It might be a week or two, depending on progress with my governor issue.

Boy, this phase I has been very active with issues to get fixed. Most are built in either by design or an assembly variance (therefore adjustable), but some, like this, could be infant mortality. A little more data will resolve.
 
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This worked for me

I replaced the solenoid on my new Skytech 149-12LS after less than a year in service with the same issue as yours. Used Duralast SS1115 from Autozone to fix the problem. Cheap and simple to repair.

I had the exact same problem. Very frustrating. I was about to send the start r back to Skytech when it read this. The part was $50, took an hour to install. Now that I know how, could do it without removing the starter and do it in about 30 minutes. Most important, it has worked on even the hottest starts.

Scott A Jordan
 
Not a fan of Skytech, I had a early one that had the nose piece break, Skytech insisted it was kick back, it was not.
Looking at the casting, there were voids in the metal. I'm lucky it didn't damage my brand new Hartzell propeller when the metal hit it.
I put a B&C on my RV7.
 
Some people will swear by skytech, I dont hear to much about the ERZ Kelly starters, but I have one been on 5 years now and it has never failed, I have beat the **** out of it once trying to start a cold engine in the winter.. the battery AGM gave out after 15 minutes of 15 seconds of cranking with 30 second breaks every minute but the starter was still going strong.
 

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Starter

I submitted a post back in 2018 when I had an RV-4 that was hard to start with an LS starter (AEIO-360 & C/S prop). After switching to the NL starter and an EarthX battery I never had another issue.

I now fly an -8 and recently swapped out the lightweight LS starter to an NL torque model. Also got rid of the 24 lb car battery and installed a 15lb PC680 to counter the prop swap and keep the CG in the right places. What a difference that makes, starts pretty instantly every time. Granted hot starts are pretty easy with a purge valve though.

I never liked the lightweight LS starters, I went through 3 on the RV-4 before switching permanently to the NL. One of the starters fried itself (not the solenoid) and the other two (which Skytec warrantied by the way) cracked the cases. The NL version is built like a tank compared to the LS.
 
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