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Discussion Starter · #1 ·
The Universal M-18 engine starts reliably every time. The recent problem is the starter motor itself.
The starter motor was replaced with a rebuilt one by a reliable boatyard 2 years ago. In the intervening time, the engine has been started no more than 200 times (part-time use), probably closer to 100. When I started the engine after a long winter (7 months) away, it started easily. Recently the starter motor starts to start and then stops. A second push on the button starts the motor as usual. Other than the momentary feeling of panic, is this a problem I should look at? Thanks!
 

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the pointy end is the bow
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When you say "starts to start", do you mean the starter begins to crank the motor and then stops?

Starters a pretty simple devices. Common failures are the starter solenoid, which is a giant high current switch. When you activate the starter, you're actually activating a magnetic coil that pulls a plunger so that a copper plate connects to copper lugs to send the high current into the motor. That plate arcs a teeny bit every time it makes contact and the arc marks degrade the contact surface, leading to sketchy behavior and eventually no starts. The manifests itself with a "click" when you activate the starter, but no cranking.

#2 are the bushes in the starter motor. Once the solenoid passes the current to the starter motor, the current then pass through some carbon bushes that are spring loaded and rest on little copper contacts on the part that spins. The bushes become worn and they don't press as hard on the contacts as they used to and the copper contacts get dirty. That will manifest itself with slow cranking or no cranking.

#3 is that the starter draws high current for a short period of time. Any poor terminal connections between the starter and the battery will cause some resistance. Resistance cuts down on the amount of current that the starter can draw upon and it also creates heat. More heat creates more resistance, which causes more heat.

Solenoids can be replaced. You can also take it apart and flop the plate over and get some life off the other side of the contact plate sometimes. Starter bushes can be replaced and the contact points on the starter motor can be cleaned up with sand paper. Connections can be taken apart, cleaned and reassembled tightly. That takes care of most starter problems in my experience.
 

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the pointy end is the bow
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Yes, the starter motor begins to crank then stops after a very short time... one second or so.
That's a harder symptom to troubleshoot. Especially since it sounds pretty intermittent at this point. Another possible problem that would cause that is the key switch itself, it's starting to fail. I would probably start there, checking for resistance at the switch itself (cheaper part to replace and it needs to be ruled out) before turning all attention to a failing starter. I feel for you though. Intermittent problems are hard to figure out.
 

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Discussion Starter · #7 ·
Thanks Wandering Star... I will check them post haste.... it might be that the first start attempt "jiggles" something (heaven knows what) to make the second start work properly.
Thank you for your advice!
 

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If it's intermittent, it's an electrical connection. Most people start with the key switch, but our experience has been the fuse in the wire between the key switch and the starter solenoid, usually hidden underneath the alternator. It's rarely the key switch.

CRITICAL UPGRADES - DO THESE OR ELSE!!!

You should also check your main engine ground connetion.
 

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Discussion Starter · #9 ·
Thanks Stu... I am a complete novice here, so when you say "the fuse in the wire between the key switch and the starter solenoid", do you mean the fuse is blown, partially blown, weak? Do all starters have this fuse?
Anyway, thanks again.
 

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the pointy end is the bow
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Thanks Stu... I am a complete novice here, so when you say "the fuse in the wire between the key switch and the starter solenoid", do you mean the fuse is blown, partially blown, weak? Do all starters have this fuse?
Anyway, thanks again.
It's a common trouble spot on Catalina 34's. The spring loaded fuse holder can get sketchy if it gets corroded, or covered in oil film, or just from rattling around for 20 years. It's not actually a fuse to the starter, it's a fuse from the starter to the instrument panel if I recall correctly. I don't know what kind of boat you have, so it may or may not apply.
 

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When you say "starts to start", do you mean the starter begins to crank the motor and then stops?

Starters a pretty simple devices. Common failures are the starter solenoid, which is a giant high current switch. When you activate the starter, you're actually activating a magnetic coil that pulls a plunger so that a copper plate connects to copper lugs to send the high current into the motor. That plate arcs a teeny bit every time it makes contact and the arc marks degrade the contact surface, leading to sketchy behavior and eventually no starts. The manifests itself with a "click" when you activate the starter, but no cranking.

#2 are the bushes in the starter motor. Once the solenoid passes the current to the starter motor, the current then pass through some carbon bushes that are spring loaded and rest on little copper contacts on the part that spins. The bushes become worn and they don't press as hard on the contacts as they used to and the copper contacts get dirty. That will manifest itself with slow cranking or no cranking.

#3 is that the starter draws high current for a short period of time. Any poor terminal connections between the starter and the battery will cause some resistance. Resistance cuts down on the amount of current that the starter can draw upon and it also creates heat. More heat creates more resistance, which causes more heat.

Solenoids can be replaced. You can also take it apart and flop the plate over and get some life off the other side of the contact plate sometimes. Starter bushes can be replaced and the contact points on the starter motor can be cleaned up with sand paper. Connections can be taken apart, cleaned and reassembled tightly. That takes care of most starter problems in my experience.
Good post Ray. I suspect bad connections too. Usually when the starter solenoid goes out, it spins openly. Not always though.

Brian
 

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Be sure the battery is fully charged and the terminals are not corroded. Clean them thoroughly and apply dielectric grease when re-attaching. If the battery wasn't properly cared for, particularly over the winter, it could be weak after three years.

I almost replaced my genset start battery this year. It would turn the motor over for a second or two and die, without starting. I would wait a few seconds and hit the start again, after the battery recovered a bit and she jumped to life. This was because she was primed up, after the first attempt. When I went to remove it, I found the terminals were corroded. After cleaning, as described above, and replacing one of the connectors, she works like brand new.
 

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Betting you will find at least one corroded terminal end. Maybe at the selector switch, if you have one in the starter circuit.but more likely in the neg side.I'm an old fashioned guy and solder all my cable terminals .
 

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Discussion Starter · #19 ·
The terminals on the starter battery look fine. In addition, the problem is not manifesting itself anymore. Maybe it only wants to do it when I am actually out at sea and ready to panic with any little glitch?
Thank you all for your help. I will keep checking things per your advice.
 
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