78 115 Merc Just Clicks After It's warmed up.

Atom 200

Cadet
Joined
May 29, 2012
Messages
6
Morning Guys,

Yesterday after solving a fuel issue on my 1978 Mercury Tower of power I found another problem. After running my boat a mile or so, Long enough to warm her up good. It won't restart. It just makes a clicking sound. However the sound is not coming from the solenoid. after trolling back to the ramp and letting the engine sit on the trailor a while it acts as if nothing happens and fires immediately. I'm at a loss.
 

oldman570

Lieutenant Commander
Joined
Mar 25, 2011
Messages
1,615
Re: 78 115 Merc Just Clicks After It's warmed up.

Was the motor pumping a good stream of water from the pee hole? When was the last time the water pump impeller replaced? Is the fuel mixture 50 to 1? When it just clicks and won't start could be the starter is going bad or the pistons are swelling and causing them to be to tight in the bore (locking up) till the motor cools down. If that is happening it needs attion ASAp or the motor will be burnt up. I would check the startor if you have good pee water and fuel mix first.
Oldman570
 

Atom 200

Cadet
Joined
May 29, 2012
Messages
6
Re: 78 115 Merc Just Clicks After It's warmed up.

It has good water flow, The ratio is spot on. the clicking noise just happens until something dries out our cools down. I dont suspect the pistons because its not an issue of turning the engine over. Its more of a getting the starter to engage problem. I guess my real question is, Is there any other things that could cause this other than the solenoid (just replaced recently ) or the starter. It seems electrical for sure.
 

Chris1956

Supreme Mariner
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Mar 25, 2004
Messages
27,030
Re: 78 115 Merc Just Clicks After It's warmed up.

I think the answer is to eliminate the starting circuit components until you find the culprit. So the next time this happens, take off the wrap cowl and feel the block, solenoid and starter for excess heat. Then use a jumper wire to connect the red battery cable on the solenoid to the thin yellow primary wire. If the motor cranks, perhaps the neutral switch is intermittant or the ign switch is intermittant. If no crank, use a piece of heavy wire to jumper between the red batt cable and the black starter cable. If it cranks, the solenoid is suspect. Also check the starter ground cable and positive cables for bad spots. Alos check battery cables for bad spots. Corrosion once reduced my battery cables to 3 strands. This corrosion was hidden under good insulation, near the middle of the cable's length.
 

Atom 200

Cadet
Joined
May 29, 2012
Messages
6
Re: 78 115 Merc Just Clicks After It's warmed up.

Thanks chris for the response. Im not sure what you mean by the switches being intermittant could you explain?
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,030
Re: 78 115 Merc Just Clicks After It's warmed up.

Well since the motor cranks when cold and not when hot, something is intermittent. I do not know how the neutral or ign switches could be intermittent, but lets rule them out, since with water and electronics, some strange things can happen. if you can isolate it to a particular component, you can replace it and figure out how it became intermittent later.... When I had bad corrosion on my battery cables, the motor would crank normally for a few seconds and then slow down as the battery cable heated up and resistance grew.
 

Atom 200

Cadet
Joined
May 29, 2012
Messages
6
Re: 78 115 Merc Just Clicks After It's warmed up.

Well, i suspect it is my starter warming up. I replaced the solenoid about a month ago. I will test it out today.
 
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