1979 Mercruiser 140 inboard

electricamp

Cadet
Joined
May 27, 2002
Messages
8
This motor has had electronic ignition add a few years back. What I am having trouble with is I will run the boat for about 20 minutes and it will just die out and not start again until it cools off. If i touch the coil after being ran for 20 minutes, its way too hot to even think about holding your hand on for 1 second. Anyone that could help me, it would be much appreciated!<br /><br />thanks in advance
 

Trent

Captain
Joined
Nov 17, 2001
Messages
3,333
Re: 1979 Mercruiser 140 inboard

While running, What is the voltage at the coil + terminal.
 

electricamp

Cadet
Joined
May 27, 2002
Messages
8
Re: 1979 Mercruiser 140 inboard

I havent had a chance to check it, but the way the coil is heating up i am sure its too high. Is there a resistor inline to that coil?
 

ODDD1

Lieutenant Junior Grade
Joined
Jan 23, 2001
Messages
1,054
Re: 1979 Mercruiser 140 inboard

YES CAMP A RESISTOR IS USED...the wire itself is a resistor, see how much voltage you have with the key on, should be lees than 10 volts [at the + term on the coil] when it dies out, does it still have spark? should jump a 1/4" gap....maybe another prob?
 

electricamp

Cadet
Joined
May 27, 2002
Messages
8
Re: 1979 Mercruiser 140 inboard

it doesnt seem to have spark when it dies out because u can just sit there and crank until the battery is dead when the coil is hot and never get one fire in the motor. Could you tell me which wire this is and how to go about replacing it?
 
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