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  1. #1

    Unhappy Ignition problem - 1986 Mercruiser 170

    Hi, and HELP! I just bought a 1986 20' Cuddy Cabin yesterday with a 170 Mercruiser. I brought it home and went to start it and just got a click. I tried again, and it seemed like I got a hum after the initial click, then nothing. On the third try, it started as soon as I hit the key. I ran it for about five minutes, shut it off and tried to start it again a few minutes later. Then (and several times since), all I get is that click, and a noticable 'bump' sound when I disengage the key. Sounds to me like when a starter is bad on a car and the click is the solenoid opening while the 'bump' is it closing, but I'm no mechanic. Some pertinient facts: 1) This is the original motor and it has right at 500 hours on it - the excellent overall condition of the boat convinces me this is accurate; 2) it has a brand new battery and cables, and is showing 11-12 volts on a meter and the dash; 3) new points and condenser were installed last week; 4) all other electrical is working fine; 5) I've tried to push the reset on the circuit breaker with no luck; 6) the in-dash fuse for the ignition switch is good. It seems that I am clearly getting juice back to the engine, but there is no cranking or anything else - just the click. I tried jumping the leads on the starter solenoid and on the slave solenoid, but the starter did not run in either case. I also checked the connections at bothe the battery and starter, and both are clean. I'm inclined to believe that I'm left with replacing the starter/solenoid unit, but would love to hear anyone's thoughts. It is just really frustrating that I had the boat home less than 15 minutes before it broke, but better my driveway than out on the water, eh? Any thoughts, suggestions or words of wisdom would be appreciated. Thanks!

  2. #2
    Ensign EddiePetty's Avatar
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    Smile Re: Ignition problem - 1986 Mercruiser 170

    ...with the random frequency of your problem, I would suspect either a dirty connection(s), defective cabling, failing solenoid and/or starter. Only a through trouble-shooting with a mulitmeter and bench test of the starter can isolate your problem.
    Eddie Petty. #3 Dirt Modified
    Courtland, Virginia
    V-20 Wellcraft
    3.7 470 Mercruiser

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  3. #3
    Cadet
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    Default Re: Ignition problem - 1986 Mercruiser 170

    Pull the spark plugs and make sure the engine isn't Hydrolocked (water in cylinders). Crank engine over with plugs out and watch for water shooting out.
    Ken LaBruzzi

  4. #4

    Default Re: Ignition problem - 1986 Mercruiser 170

    Quote Originally Posted by EddiePetty View Post
    ...with the random frequency of your problem, I would suspect either a dirty connection(s), defective cabling, failing solenoid and/or starter. Only a through trouble-shooting with a mulitmeter and bench test of the starter can isolate your problem.
    Well, actually the problem is pretty static - it does the same thing everytime, unfortunately I'm pretty sure it is a bad starter/solenoid, and paln to pull that unit out tomorrow and have it tested and rebuilt if necessary.

    I didn't mention in my earlier post that the previous owner had it out last week and started it up several times this week, including in my presence. My sense is that the first couple of times it didn't start for me was because it was starting to fail... and then finally did.

    One question: if for some reason the engine seized up, would I be getting the same result, with the starter unable to move and thus just having the solenoid engage and disengage? Also, I don't know how to test for a hydo-lock if I can't get the thing to even turn over... ?

    Thanks guys.

  5. #5
    Commander Eric 3.7LX Alpha 1's Avatar
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    Default Re: Ignition problem - 1986 Mercruiser 170

    Pulling off the plugs and cranking over the engine will tell if there is a problem with the engine. There is no compression on the engine with all plugs out and super easy to turn over, either by hand or with starter.

  6. #6
    Chief Petty Officer
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    Default Re: Ignition problem - 1986 Mercruiser 170

    Mine would do that and it was loose wires on the ignition switch. Is the click from the starter solenoid or the slave soleniod/relay?

  7. #7

    Default Re: Ignition problem - 1986 Mercruiser 170

    Not sure, but I can check. What would be the difference?

  8. #8
    Master Chief Petty Officer Blk-n-Blu's Avatar
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    Default Re: Ignition problem - 1986 Mercruiser 170

    Time to take a trip to the "Adults Only" Stickey where Don S has some diagnostics for you:
    http://forums.iboats.com/mercruiser-i-o-inboard-engines-outdrives/how-troubleshooting-your-engines-starting-system-167035.html

  9. #9

    Talking Re: Ignition problem - 1986 Mercruiser 170

    As I thought, it was the starter... just finished putting the new one in and she fired right up and is purring like a kitten!! Thanks all for your helpful comments and suggestions.

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