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Fuel flooded starter motor wiring

wynjim55

wynjim55

Regular Contributor
This post is more of an awareness raiser than an issue that needs solving. For some time I have been having intermittent problems with my starter motor which I assumed, due to age, was caused by poor wiring connections or worn brushes inside the starter motor base. The motor sometimes works excellently, and then without warning it labours to turn, then comes good again after a short wait. Today it struggled and struggled but got no better. Turns out I was way off.

Today my son brought my attention to a fuel leak, on closer inspection I found it was caused by a loose fuel hose on the back of the fuel line connector (where tank hose meets outboard cowling). A zip tie around the offending junction to replace a worn out spring clip soon fixed the problem. While cleaning the area I located an open wiring connection where the electrical tape had come unstuck, most likely due to fuel spray, around the fused +ive wire to the starter motor. I promptly overhauled the connection and replaced the well meaning tape with heat shrink plastic tubing. In the process I removed the fuse at the end of the wire to find the fuse holder was holding an amount of fuel. I dried it out, finished the wiring fix and put it all back together. The starter motor instantly came good and fired up the old 1978ish outboard with ease.

Today was the first time I had seen the fuel leak and given how much was leaking it would be impossible to have missed it previously, I can only assume it had worsened since the last use. The fire hazzard of leaking fuel and exposed wiring should be blatantly obvious to everyone. Hopefully this only serves to show how important regularly inspections or servicing is. Thankfully I didn't have any complications due to this event, and I found it while preparing for tomorrows outing, better to find and fix these things on dry land and not when stranded on the water. I always carry tools and spares just in case but much prefer to work on a flat surface with a coffee and a spare parts shop nearby.

Happy boating
 
Thanks for the tip. My 115 HP starter has an issue when the engine is first started. It will crank but after several short cranks and no fire the starter begins to "drop off" of the flywheel and moan when I hit the key start. I took it apart last winter thinking it needed brushes but found them in excellent condition. The armature was colored blue/purple/black from high current heat. I scuffed and filed the armature to reveal a clean copper surface and under cut it to remove the brush debris between coils. I oiled the bearings, installed a new spring and reassembled it...still does it. I even replaced the solenoid to no avail.
 
Possibly a poor wiring connection in circuit to throw pinion gear into place, or low output solenoid. When I first pulled apart the starter motor for my outboard I found that the plunger inside the solenoid was corroded in place, maybe yours just needs a bit of a clean to reduce friction. Any maybe, like so many other times, I'm on the wrong track.

Today my boat performed flawlessly, starter motor and all :D
 
I even replaced the solenoid to no avail.
Click to expand...
I think it is heat related since it doesn't happen until after several 5-6 second cranks on the starter. The evidence was seen on the armature's commutator...blue/purple copper. I found it improves starting by holding the key in for 10+ seconds on initial startup allowing the enrichener valve to give it a good dose of fuel. The engine starts in 1 second of turning the key the rest of the day...it's just the initial start after laying up for more than a week. If it won't start after 2 attempts of the key turn then I reprime the bulb a second time until it firms which usually does the trick.
 
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