Merc 150 won't turn

[marioone]

I recently purchased a boat with Twin Mercury 1996 150HP, needless to say it needed some TLC. I've always had engine starting issues due to carb issues (fixed with 100 hr service plus carb tune up) but even since then still always a challenge to get going. I guess I haven't quite figured it out yet. Since the batteries were about 5 years old I put in 3 new batteries this weekend and took her for a spin to see if she would be ok. Port Engine started ok with some TLC and the sstarbord one, no go.

I left on one and took a closer look when I got to my destination. When I looked down below I realized I forgot to wire the ground that comes from one of the batteries and goes to the starter on the starbord engine. I connected it and after a couple of attempts to turn it over it turned. I let it run for a couple of minutes and turned it off while we were enjoying the beach. An hour or so later I tried again to turn it over and nothing. I can hear the Starter solenoid clicking but no go. I spent some time taking a looking at it last night but not sure. The service manual has a troubleshooting flow chart but I can't follow it since I can't tell where some of the components are.

The port engine has a Deep Cycle and a Dual Purpose battery on a 1/2/both switch and the stbd has a marine starting battery which i think is 650 or 800 CCA.

What do you think could be going on here? What can I be checking before I shell out some $$$ to have someone look at it.

Thanks

Engine Model: 1150425SD MERCURY 1996 150

 

[Chris1956]

Re: Merc 150 won't turn

Sounds like the motor is not getting any battery power to the starter. Of course with three batteries, there could be other issues. How is each battery connected to each engine? You have switches? Combiners? Isolators?

 

[marioone]

Re: Merc 150 won't turn

Here's what I've been able to diagram, I'm missing the ground to the engines in the diagram.



Bank 1 consists of 1 battery connected to the on/off switch, this connects to the engine (stbd) that won't start.

Bank 2 consists of 2 batteries connected to the 1/2/both switch (combiner?) which provides juice to port and starts after a couple of turns.

There is no isolator, however the previous owner had a solenoid for an emergency start swtich that I'm told is supposed to provide a jump start if needed. It's never worked for me but current is flowing through the solenoid, I 've just never seen it bridge it.

This is my 3rd month in to boating so just trying to learn... patiently.

Thanks!

 

[marioone]

Re: Merc 150 won't turn

Bump.

 

[CharlieB]

Re: Merc 150 won't turn

........................... I can hear the Starter solenoid clicking but no go...................................

Engine Model: 1150425SD MERCURY 1996 150

The battery diagram is functional, as long as all connections are clean bright and tight, they are not the problem.

The starter solenoid or starter is your issue.

Grab your trusty battery jumper cables and jump directly from the battery to the starter, it it spins fine, replace the solenoid as the contacts inside are marginal.

 

[marioone]

Re: Merc 150 won't turn

Just came back from some troubleshooting and it was the starter solenoid. I took the one from the functioning engine and put it in the non functioning one and it worked.

Wondering if I should replace both since they've always been a challenge to start. Maybe 2 new ones will makes things better?

 

[CharlieB]

Re: Merc 150 won't turn

Clean ALL cable connections bright and tight.

Starter commutators get dirty, brushes wear, if the jumper cable trick makes no difference then it may be time to service the starter(s).