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Starter issue has me baffled?

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  • Scooter2shoes
    started a topic Starter issue has me baffled?

    Starter issue has me baffled?

    Hey guys, newbie to the forums but figured i needed some help on this one.
    Working on a 1987 edson 17.5 bow rider with a 170 merc inboard with the alpha one drive, boat ran when parked 3-4 years ago. Went to fire it up the other day to get it ready for my deceased fathers estate sale and it has me just baffled as to what the heck could be wrong!
    When i try to crank it over it just activates the solenoid, and then will not disengage unless i turn off the power at the battery select switch, by which time the ground cable is smoking.
    Firstly i checked and cleaned my grounds to engine block and transom, no change. Tried using booster cables to ensure proper ground between battery and engine and also between starter and block or battery, no change either way.
    Tried disconnecting ignition wire from ignition switch then using jumper wire to see if ignition was sticking, well i hit the key and the starter engages, let off the key, starter stays engaged, i inhook my jumper wire from ignition and it continues to try to crank. So that’s eliminated.....
    Also tried just jumping the starter with a screwdriver while ignition unplugged to confirm, again keeps trying to crank until i kill the power at the battery switch.
    Bit the bullet, bought new starter with solenoid, still does it!!!!
    Now heres the weirdest (to me) part, i unhooked all the wires from the starter except for the main power feed, (disconnected the two other wires off of the main power terminal that go the the voltage regulator, and also unhooked the ignition wire), and as soon as i turn on the battery switch, it tries to engage and melt my poor ground cable again!
    i dont get it, could it be something with the stator shorting, anybody have any ideas?
    Also i should mention ive gone round and round and upside down the harness looking for shorts or burns with no luck unless its in the circuit breaker or voltage regulator or something. Any help would be greatly appreciated, thanks in advance.

    Also worth mentioning that the engine only really turns over with the plugs out, but not fast by any means, its not growling or rough per say, just seems like the starter isnt getting sufficient power even if i just jump it directly with booster cables.
    With 3 bolts in the balancer i can easily turn it over with a small bar and it rotates smoothly, but starter seems to be really struggling to crank it?
    Again, thanks in advance.

  • Scooter2shoes
    replied
    Originally posted by Chris1956 View Post
    OK, not to rain on your parade, why did a valve decide to stick suddenly? Rust from the cooling system? Cracked head? rusted manifold?
    I would have to say just from sitting for 4 years! Atleast im hoping!

    Leave a comment:


  • Chris1956
    replied
    OK, not to rain on your parade, why did a valve decide to stick suddenly? Rust from the cooling system? Cracked head? rusted manifold?

    Leave a comment:


  • Scooter2shoes
    replied
    Okay, got it figured out!!! After draining the leg and seeing all the milk in there i figured it might be adding a bit of resistance, but upon trying to crank afterwards it was not the problem. So i went plug by plug removing each one, one at a time until i found one that while pulled, allowed the engine to turn over easier. Happened to be #2, anyways i then pulled the remaining plugs, gave each cylinder another shot of oil for extra lubrication, then pulled the valve cover off and bathed the valve springs in motor oil with the hopes it would make its way down to my sticky valve(s). After letting it sit for around and hour then trying to crank the engine, it made about revolutions then suddenly cranked like it was supposed to! I replaced plugs, hit the key and it cranked over great....... but no spark, then after a quick test of ignition system, followed by setting the points, it fired right up and runs great.
    Thanks all!

    Leave a comment:


  • JASinIL2006
    replied
    Actually, I think you'll want to be in forward to pull the outdrive.

    Leave a comment:


  • Chris1956
    replied
    sure, pull the outdrive. Mercruisers need to be in reverse to pull the OB, if I remember correctly.

    On that vintage Mercruiser, you are supposed to grease the U-Joints every year. Have you been doing that?

    Leave a comment:


  • Scooter2shoes
    replied
    Originally posted by Chris1956 View Post
    With motor in neutral, starter will turn U joints, upper gearcase gears and lower gearcase gears. If the motor is in neutral, it will not turn prop shaft.

    I would expect battery voltage to drop lower than 12V when cranking. That points to dirty connections. The battery ground is bolted to the block. They do get corroded, leading to high resistance.
    The ground terminal in the back of the block was about the first thing i checked, wasnt corroded badly but cleaned it right up with emery cloth to be sure, then after multiple other things i decided to bypass all the boat wiring and hooked a set of heavy booster cables directly to starter(to ensure good connections and eliminate boat wiring concerns) and it still wouldnt hardly crank with plugs in, after pulling the plugs it cranks better but still not what i would expect.
    Last night i thought maybe mice build a nest inside exhaust somewhere so i unbolted exhaust manifold, pulled it clear of head, and again, with the spark plugs in it just barely cranks...........
    I wonder if there is excessive resistance coming from drive gears or u-joints?
    Without pulling the engine to check, is there any other way to check?

    Leave a comment:


  • Chris1956
    replied
    With motor in neutral, starter will turn U joints, upper gearcase gears and lower gearcase gears. If the motor is in neutral, it will not turn prop shaft.

    I would expect battery voltage to drop lower than 12V when cranking. That points to dirty connections. The battery ground is bolted to the block. They do get corroded, leading to high resistance.

    Leave a comment:


  • Scooter2shoes
    replied
    Yes cables are hooked up correctly, and after now trying a second “new” starter, even jumping the starter directly from battery (tests at 12.5, load tests at 12.0v) it cranks very slowly with plugs out, not at all with plugs in. Going to see today if maybe shift selector isnt working and maybe the starter is turning drive unit as well as that would explain the excessive drag. Will post results tonight.
    Any help or advise at this point would be great, come on people!!!!

    Leave a comment:


  • Bt Doctur
    replied
    battery cables hooked up correctly? pos to pos?

    Leave a comment:


  • Scooter2shoes
    replied
    Okay so slave is functioning properly, another thing to note is when i have the battery and chager set to boost mode hooked up and i try to crank it, my voltage reading taken from the starter feed from solenoid only reads 3+/- volts. When i hook up my vm to the power cable going to the solenoid it reads 17v until i crank it, then it also drops to 3v+/-, then i have to kill the power at the battery switch as the solenoid seems to still be sticking until i kill the power then i can hear it disengage..... when i turn the power switch back on it reads 17v again. Disassembled the starter again, checked brushes, bendix ramps for debris, cant find anything obvious that would cause the massive drag and draw. ARRRGGGHHH!

    Leave a comment:


  • Scooter2shoes
    replied
    After going over the wiring diagram i noticed that slave solenoid, was going to check it later today, still cant figure out why the starter engages with only main power feed hooked to it, and no ignition wire connected to trigger it! Starter solenoid must have stuck on that occasion.........
    Also forgot to mention that the starter functions normally when not mounted properly, instead i ratchet strapped it to the exchanger and hooked up all the wires, works like a charm, but then when i bolt it up into place the problem returns.

    Leave a comment:


  • Chris1956
    replied
    Some of those MerCruisers have a slave solenoid in to assist the starter solenoid. Maybe that one is sticking? Look on the engine block for it.

    Leave a comment:

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