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sky tec starter failure?

avengingangel

Well Known Member
ok, this is a continuation of a thread i started titled full river battery. There was a few following it already, but i'll throw this question out to all since it's about the starter.
after checking wiring, battery and grounds. No parasite drag. Engine cranks extremely slow.
Metered the current draw of the starter installed. Showed 480 amp first try second 520. Also starter seemed to have a slight growl, kind of sounded power related.
Also after cranking, all connections are cool except the stud between the plunger and starter motor.
I've removed the starter and my ame wants me to have a closer look at.
Would it be the moter itself if the heat is coming from that area, what else?
Starter is a 149-12lsx about at most 3 yrs old. current draw for these starters look to be 160-280amp.
 
If the rotor bushings are worn the rotor could be rubbing against the stator , there will be no drag until the magnetic forced pull on the rotor, take it apart and look.
 
Call Sky Tec Monday.

This is a simple suggestion based upon my ignorance of how a starter can fail and the symptoms of various failure modes. Please report back with your solution so I can learn from this event.
 
Also if you are pulling 520 amps you definitely do not have a wiring problem, got to be mechanical drag somewhere.
 
sounds good.
I'm going out in the shop now to dismantle.
i will also call sky tec tomorrow. I'll let yas know on what I find.
thanks guys
 
Take a good look at the mounting face of the starter, there was an issue awhile back with a locating pin that was causing problems----up to actually cracking the housing.
 
well, end cap bushing has failed. probably pinion end too. So, I suppose there will also be damage at magnets and armature.

so, this whole problem has been starter and mechanical binding.
this has been an interesting cranking problem, if the previous thread "fullriver batteries" was followed. always handy info to know.
 
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seems to be a few things wrong with this starter.
well, I think the starter is in very poor shape.
1. the brushes have slivers or chunks broke off them to the point i would estimate about 70% brush to commutator contact.
2. have found chunks of what are probably carbon but possibly magnet.
3.magnet placement. I'm no starter expert but this could be part of the design but I have never saw it before. my magnets are out of alignment, one magnet would be at least half an inch out. there's clips holding them in place. and it looks the clip has actually moved. Is there an adhesive that actually holds the magnet also? otherwise these things have migrated south on their own.
going to have a beer now and them clean the ends of the magnets because i think they may be chipped also.
i think this starter is what we call grenaded. any thoughts.:)
 
oh I forgot
the inside of the end cap is showing wear from contact with commutator. not surface but the end of comutator.
 
At the risk of being redundant, a call to Sky Tec should reveal what they will do for you. Possibly full replacement under warranty or low cost replacement.

Then the question is what happened? Was it a starter issue so a replacement solves all problems? Or could something have happened that started the damage to the starter. Can't help with those questions.
 
yes, I'm very interested in finding why. Maybe kickback, I dunno. I'm sure they'll have a good idea. look forward to finding out.
 
ok, called skytec this morning and they were very helpful.
more than likely it's suffered a kickback. once i told him about the magnets he was quite sure.
As to the reason it is also known.
lightspeed ignition is natorious as a culprit for this problem. if the conditions are just right and voltage is low enough the advance and retard spark may not work as it should. At some point of time i think i may have ran the battery down enough last summer during a hot start which probably caused this.

the starter needs a rebuild.
 
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No, your starter needs to be replaced. Those smaller, lightweight Sky Tec starters are JUNK, and they are the wrong starter for a O-540 engine. There's been numerous threads about the kickback problem and permanent magnet starters. If you put another one in, it will just break as well as many more before you have learned.

Your best bet is to see if you can use it to trade up. The NL starter that they offer is a really good starter and has a lower gear ratio than the equivalent B&C starter and it does a great job of turning over the O540.

Word to the wise.
 
you have the b& c dont you? i think they have these here as ac spruce. What model is yours? it has the solinoid attched to it does it?
 
I had the B&C on my first Rocket and the Sky Tec on the EVO. I actually like the Sky Tec better.
 
Lightspeed ignition is natorious as a culprit for this problem. if the conditions are just right and voltage is low enough the advance and retard spark may not work as it should.

Not true! The advance and retard have nothing to do with how low the voltage is and if you have enough voltage to turn the starter there is more than enough to power the LSE. LSE will work to below 6V. The Sky Tec is known to draw huge amounts of current.
 
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Not true! The advance and retard have nothing to do with how low the voltage is and if you have enough voltage to turn the starter there is more than enough to power the LSE. LSE will work to below 6V. The Sky Tec is known to draw huge amounts of current.

oh ok then. You better contact skytec and tell them their tech is wrong.

anyway, I dont really care because things are working the way they should and I'll be starting it off the right mag as he suggested because it works fine that way too.
 
Not true! The advance and retard have nothing to do with how low the voltage is and if you have enough voltage to turn the starter there is more than enough to power the LSE. LSE will work to below 6V. The Sky Tec is known to draw huge amounts of current.

I'm sure the LSE's will fire down to ~6V, but it doesn't mean they always fire at the correct time with the first pass of any given magnet past a sensor. My IO-360-A with dual LSEII's and flywheel trigger has backfired a few times, immediately when engaging the starter. Hasn't broken my Skytec LS starter yet, but my starting procedure now is to start cranking with the ignition OFF and once the prop makes a revolution or two, then turn on the ignition. Never get a backfire that way, and still starts almost immediately.
 
I'm sure the LSE's will fire down to ~6V, but it doesn't mean they always fire at the correct time with the first pass of any given magnet past a sensor. My IO-360-A with dual LSEII's and flywheel trigger has backfired a few times, immediately when engaging the starter. Hasn't broken my Skytec LS starter yet, but my starting procedure now is to start cranking with the ignition OFF and once the prop makes a revolution or two, then turn on the ignition. Never get a backfire that way, and still starts almost immediately.

On previous units working with the high current draw Skytec, the prop would stop after passing the first trigger and it would back up and pass this trigger again which gave the spark. To correct this when Skytec starters are used a fast reset was installed so that the second trigger at -45? appeared as the first as it should be. Klaus had to do a lot of analysis to find out what was happening. It's interesting that a Skytec technician knows all about the LSE ignition.
 
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