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ignition switch or solinoid or shower of sparks??


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Just got my prop overhauled.  Started it (on the first blade) and did a full runup.  Everything good.  Call the gas guy.  Load up the friends.  Try a hot start.  wont start.  Kept trying but the push to start in the switch was getting more and more finicky.  Had to do little jiggles and side push to get the starter to engage.  Finally it wont throw the starter out at all.  I can hear the shower of sparks noise and when I press in I just hear a click/clunk but nothing happens.

Unloaded pax.  Drove.  grumble.

My mechanic happened to be working in his hangar listening to me try to start it.  He said I need a new shower of sparks.  Seems to me I can hear it doing its shower thing.  My ignition switch has always been finicky.  But as I sit here typing I'm wondering if I overheated the starter.  This would be by far not the longest I cranked it but ...  I think I'm going to go over to the field today and see if it will turn over now that the starter has cooled off.

Thoughts?

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First indication is the starter switch. If you had to "jiggle" it to make it run, start here.

Most can be taken apart and cleaned and lubed. If its broken, replace it ($$).

If the prop won't turn (starter dead) it ain't the SOS. 

Have your A&P jump the leads on the start solenoid  to see if the prop will turn. 

Check battery charge (hydrometer check), start solenoid check for high resistance, all battery cables to starter for good clean connections AND make sure you have a good ground wire from the battery to the airframe.

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2 hours ago, TheTurtle said:

not sure.  its not one of the hightorque light weight ones though.

If you have the original Prestolite and you don’t hear it spinning, you probably need a new solenoid. If you do hear it spinning you probably need a new bendix. 

If it is the bendix, you can try hosing it down with Tri-flo or silicon. Don’t use anything that leaves an oily residue it will just collect dirt and make it worse.

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2 minutes ago, teejayevans said:


In my experience that’s a very temporary solution and will fail when you are away from home.

Yep, I agree completely. But it may get you going for a while. 

If you get stuck away from home, use a long screwdriver to manually engage the bendix. Easy on an F quite a bit harder on a J.

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21 hours ago, cliffy said:

First indication is the starter switch. If you had to "jiggle" it to make it run, start here.

Most can be taken apart and cleaned and lubed. If its broken, replace it ($$).

If the prop won't turn (starter dead) it ain't the SOS. 

Have your A&P jump the leads on the start solenoid  to see if the prop will turn. 

Check battery charge (hydrometer check), start solenoid check for high resistance, all battery cables to starter for good clean connections AND make sure you have a good ground wire from the battery to the airframe.

This 

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18 hours ago, teejayevans said:


In my experience that’s a very temporary solution and will fail when you are away from home.

I've had the opposite experience - when i got my C model last fall, it would "ziing" in cold weather on the first attempt, then engage on the second.  Hosed it with some tr-flow, and haven't had a problem with it since December.

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Good news.  I think I just overheated the starter.  Went out today and it fired up on the second blade.  Now to figure out why shes being such a bitch hot starting lately.  I thought I had my hot start method down pretty well but even that is failing me the last couple months.  

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I found David's process very productive with my E...   search google for "Hot Starts M20E interview with David McGee"       

Im usually running in 1 or 2 start attempts of 15secs of starter engagement...  Just get in the habit of 1000 rpm shut downs... 

that throttle position works well for myh cold starts too...  

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On 9/3/2018 at 7:05 PM, TheTurtle said:

Good news.  I think I just overheated the starter.  Went out today and it fired up on the second blade.  Now to figure out why shes being such a bitch hot starting lately.  I thought I had my hot start method down pretty well but even that is failing me the last couple months.  

I have a technique, but we are talking black inky magic on the hot start of my E.  I can get it started, but sometimes it is pretty “cranky” if you get my gist... :)

Good for you that you have it “down” pretty good.  Me?  Not so much.

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On 9/3/2018 at 7:05 PM, TheTurtle said:

Good news.  I think I just overheated the starter.  Went out today and it fired up on the second blade.  Now to figure out why shes being such a bitch hot starting lately.  I thought I had my hot start method down pretty well but even that is failing me the last couple months.  

Nothing has fixed itself though. Whatever it is, it is so much cheaper and convenient to get it taken care of at your home field rather than getting stuck somewhere. Usually you get some warning signs before a starter goes completely. I think a new starter is in your future.

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My experience with Shower of Sparks.

1) if your battery is weak your Shower of Sparks (SOS)  will be weak and may not provide enough spark to start

2) If you release the starter while engine is spinning this will allow the mags to do their thing and thus probable the engine will start  --  The (SOS) system shorts out the mags, which is problematic with both a weak battery and the SOS not working.

3) It is my belief that if the SOS is buzzing it is working, albeit with a weak battery may not be producing sufficient spark to start.

4) If the spark plugs have too much resistance, as in old or partially fouled, they could also cause a need for more electric pulse than the SOS is providing.

5) there is a set of points within the SOS that sometimes need cleaned/filed --  SOS manual referenced above does give the point gap setting.

Just a PPL so the above is not gospel but just my experience/opinions, but number 1 above causes all kinds of problems with the SOS.

Good luck

 

 

 

Edited by N9434V
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