Need Help - 1995 100HP Mercury

wavers

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Mar 31, 2008
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Hello: I own a 1995 Mercury 100HP outboard. It has been an excellent motor until last summer. I ran out about 6 miles to my fishing spot and returned back to my slip w/o a problem. The motor ran great. However, when I returned back to go out for the evening, my motor would not turnover. It was getting gas, sounded like it wanted to start, but we determined it was not getting a spark. After calling the on-call mechanic for the resort, we found the Voltage regulator had burned out. We thought that was it. However, upon futher review...it was not the cause of the trouble. Fuse was good as well. Could it be a solenoid? If so, how can I tell which one is bad? I did have 2 replaced a year ago. If it's not a solenoid, what do you think it could be. I would really appreciate some help on this.

Thanks in advance.

Joe
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Need Help - 1995 100HP Mercury

Howdy, Wavers.

Welcome to iboats. :)

Wiring/cable connection from battery to solenoid, battery to engine block, solenoid to starter are all suspect, as are the battery connections and cables.

This is a very common problem and is usually considered too simple to cause so much grief.

Check it out. Do not consider a tight connection good. Take them off and clean thoroughly.

Good luck. :)
 

wavers

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Mar 31, 2008
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Re: Need Help - 1995 100HP Mercury

Hi JB:

I am glad I found this sight and I look forward to resolving my issue. Does your suggestion apply if the starter is engaging and the volt-meter is reading just over 13 volts. Sorry if I am not using the correct terms.....I am technically challenged.

Thanks
 

wavers

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Mar 31, 2008
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Re: Need Help - 1995 100HP Mercury

I still could use some help at least another opinion.

Thanks
 

CharlieB

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Joined
Apr 10, 2007
Messages
5,617
Re: Need Help - 1995 100HP Mercury

I could write a whole book, but first a number of questions.

LAST SUMMER?

Has this boat been run since then, was it winterized or fogged?
Did the tach work when it was last run? Tach quits when a regulator dies.
How long did you try to crank it with the low battery, long enough to cook the starter?
Have you pulled the spark plugs and turned the motor/flywheel by hand to ensure that the motor turns freely?
Follow JB's advise, throughly clean and tighten ALL battery cable connections, both ends.
Remove the spark plugs and install a spark adaptor/checker then try the starter, does it turn over at an acceptable speed without the plugs? A weak starter may crank OK with no compression but not crank or crank slow with compression.
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Need Help - 1995 100HP Mercury

If the voltmeter (I assume battery voltage) doesn't drop to about 10volts when the starter is engaged that is more evidence that the circuit has some resistance and the starter is not getting enough current.
 
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