Starter motor maintenance -4108m

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This topic contains 8 replies, has 5 voices, and was last updated by Van Van 4 months ago.

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January 26, 2019 at 15:13 #26530
John Tyler
John Tyler
Participant

I have just had my starter motor reconditioned – rusted up – and wonder if anyone else has any info on how to avoid a rusty starter. I have a 4108m & 2 pin starter motor.

There seems to be a few points:

1. Do owners grease the join between the starter & engine block or use a gasket maybe?

2. The sump area below the engine & starter can get wet and the starter is low lying anyway, so prone to damp etc. I am considering drilling the sump rear wall by the starter to allow any excess water to drain back into the bilge below the drive shaft – easier to drain with sump drain pump than the actual contained sump area directly under the engine.

February 5, 2019 at 08:49 #26534
Van
Van
Participant

Hi John,

Timely question – I was just today looking at my 4-108M starter motor and thinking “ugh, that’s rusty, I wonder if I should be worried”.  I think the rust is superficial, but must admit I have no confidence in that.

What should we do to protect it?

I’d be hesitant to drill the sump wall to allow liquids to drain into the bilge – that could include oils like diesel if you had a crack in a high pressure hose.  Your bilge pumps would end up pumping the diesel overboard.   We had just such a leak, and it was contained in the pan under the motor.

A related question – as we prepare to head off into remote areas of the S Pacific, should we be carrying a “spare” starter motor?

Van

 

February 14, 2019 at 20:53 #26552
John Tyler
John Tyler
Participant

Hi Van

Interesting what you say, as always. I did drill the hole but it is plugable to contain oil spills etc. I got my ‘newly serviced’ starter out again today as it was already rusted & the bendix would not slide along the shaft to engage the flywheel. I am now considering Kurust then thin Primocon paint to try & keep the gear rust-free. I wonder if an always-engaged starter would be possible on a 4108m, thus eliminating the need for the bendix to slide along the starter shaft.

Any ideas on this last point?

February 17, 2019 at 18:14 #26553
Van
Van
Participant

Ah, this is beyond my domain of expertise!  For me, the 4-108 is the “beast” below the cockpit sole that I struggle to tame and keep happy…..

I like very much the idea of a plugable hole in the pan.  We just had our raw water pump start to leak (there is a special drain hole designed to leak water if the shaft seal fails, and that’s what happened).  Fortunately we spotted it after only a liter or so of water ended up in the sump.  But if it had been much more than that, I would have been happy to be able to pull a plug and drain it into the bilge for the pumps to deal with.

February 20, 2019 at 16:24 #26554
John Tyler
John Tyler
Participant

Hi Van

Good luck as you deal with/enjoy the Pacific. Re starters, I am going to get a spare. I think the chems used when the motors are cleaned often causes a deterioration in the ‘marinisation’ quality of the starter metal. The guy who cleaned mine will let me have one for £100/ $120 US, but I will buy new & hope the metal is more virile in anew one! At least they are relatively to get on/off and McLube is something to keep the metal marinised [of sorts]

Ciao

John

March 5, 2019 at 19:04 #26557
PeterM
PeterM
Participant

Hi all,
I will add my starter motor story for what is worth…
We burned the starter motor out because the key switch did not spring back to the run position. The diesel started and ran fine, but the starter ran also, and the next time trying to start up, the solenoid clicked, but nothing else.
Our engine panel is now a pushbutton for the starter, so I think this is less likely, but a cautionary tale…
and of course we were in a really remote location for getting parts…
since then we have carried (the rebuilt) spare starter motor everywhere…

Peter M

April 9, 2019 at 20:45 #26570

Rhapsode
Participant

Here’s another story…

Our starter motor was playing up so we asked a starter motor man in Trinidad to take a look at it. He found the brushes were a little worn but nothing else.

I put it back on and we sailed up to Carriacou and then found it was still not working properly. The mechanic there diagnosed a solenoid problem. It being a sealed unit I thought I’d have to get a new one. Not so! The mechanic cut it open, cleaned it up and then welded the two halves back together again!

It’s behaved impeccably ever since. But a spare is on order!

June 11, 2019 at 04:05 #26603

Murray Smith
Participant

Just like Peter M, my key start switch did not disengage and I also burnt out my starter.  As this happened while I was being launched last week for the season, I had more on my mind and didn’t realize the starter was still engaged in time.  Besides the starter, I replaced the key start switch with a better spring action release.

 

June 17, 2019 at 04:16 #26606
Van
Van
Participant

We had a similar problem but happily no burned out starter.

Our solenoid stuck in the “closed” position and the starter motor would not stop in spite of the ignition key position.

Luckily, we heard it, and jumped down below and killed the battery switch which stopped the starter.  Turned the switch on again, and the starter immediately started.  Well, it was like a new ignition switch, only big and red!

At that point, I took a large wrench and smacked the solenoid a few times.  (I can assure you, this was done, not in anger, but as a calm, controlled, well-thought out action).  This fixed it, and we have had no more problems.  On and off just as designed.

I am due to change the solenoid as soon as I get out from under the giant list of other things to do.

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