My 120 won't start anymore, Help

First of all I am not a mechanic, but since I don't have an abundonce of cash, I do all my own work.

My 1984 Mercruiser 120 was working perfectly for the past couple of months. After driving over to the marina this weekend to drop off some people...it won'r start. Won't even turn over. I here clicking, which I assume is the solinoid but I am no expert. I bought a manual to see if I can deduce what parts are what before sticking my screwdriver down to jump the connections. I have done this hundreds of times on outboards but never had an inboard until this one.

Any ideas I should check before pulling this thing apart?

Ken

try a different battery,soft click(slave solenoid) loud crunch(starter solenoid) ,
check engine oil , remove sparkplugs to check for water,
start at the slave and jump the larger Red/purple and yel/ w stripe,should turn the starter

tried another battey, no luck. I even hooked up my charger and set it to 'boost", same sound.

I jumped the slave and other than some sparks, nothing, not even the a click.

the sound is more of a CLACK when I turn the key.

Checked the oil, brand new and up to the full line...I was watching the oil preasure too and no problems there before this happened..same with temp.

slave should have tripped the start solenoid, either the starer got wet at some time and is bad or the solenoid is bad.

Oops, my other post about the age of the engine stated a conversation like this one...

I am moving chiefalen's post here and commenting on it.

I had that motor for 5 years. But pushing a stringer, now i have a merc 3.0. them 20 hp doing my bidding makes my boat feel and run so much better i couldn't believe it.

Why the chief just wrote that chit is, even if this motor is toast your can get a good 3.0 for under a grand fair price 800.

Ok to your problem:

1- The battery charged?

2- cables good ? Don't just look at em clean the lugs on the battery and then clean, the cable ends and inspect them.

3-The connections on the solenoid ? Clean ?

4- Connection on themain neg cable ground ? Follow it to the block remove and clean.

5- You at it anyway and you knew to remove the cables off the battery so why not clean the starter and any other connection say at the coil clean and shiny.

6- look at the oil sender t-stat sensor they are all in reach if your on the starboard side cause thats where all the connections are, maybe clean them also.

Then hook up the fully charged battery.

Put water to the drive and have it down and try to start it.

Still clicking ? If yes jump the solenoid, it turn the motor? No ? Jump the starter.

Still don't turn ?

Pull all the spark plugs out, try turning it , first with the starter and then with jumping the solenoid then the starter.

Still no turn, pull the drive. Try turning it.

No turn ?

Motor seized, starter shot, one or the other. Try turning the motor by hand, that will tell which one.

Post back maybe you will have grace smile on you and you have to get a 3.0 at the time i was cursing and screaming but now i wish i did it before i bought a head for the 120.

Ok here goes...took me a while to do all of this but I'm back.

Battery is good and charged

Cable ends are brand-new and heavy duty. just installed them last week, so absolutely no issues there.

Cleaned ALL connections in the starboard side..even the oil sendor. Nothing looked bad enough to cause a problem. Dropped most of the damn lock washers in the process....what pain getting them from under the engine.

Still not working.

I was able to pull all the plugs and manually turn the lower pully a smidge...so I assume it's not siezed. Damn it;s hard to get your hands in there.

how can I jump the solinoid? which wires...red and yellow?

Thanks you guys this is wonderful.

For what it's worth, solenoids can click and not pass current due to worn or corroded contacts.

how can I jump the solinoid? which wires...red and yellow?

Click to expand...

Ayuh,... Apply battery power to it with a jumper wire...
If the starter don't spin, replace it...

you can tap the starter with a hammer, tap not smack it like a cheating wife. On the starter solenoid.

KenL said:

Ok here goes...took me a while to do all of this but I'm back.

Battery is good and charged

Cable ends are brand-new and heavy duty. just installed them last week, so absolutely no issues there.

Cleaned ALL connections in the starboard side..even the oil sendor. Nothing looked bad enough to cause a problem. Dropped most of the damn lock washers in the process....what pain getting them from under the engine.

Still not working.

I was able to pull all the plugs and manually turn the lower pully a smidge...so I assume it's not siezed. Damn it;s hard to get your hands in there.

how can I jump the solinoid? which wires...red and yellow?

Thanks you guys this is wonderful.

Click to expand...

with a Voltmeter and someone turning the ignition switch find out if it is a solenoid or the starter motor ,,,if the voltage does not drop very much at the starter input it may be the brush is hung up or corroded commutator...

if the voltage at the starter drops and no rotation it could be the engine is seized/hydo locked etc...

as mentioned before with the plugs out try to rotate the crankshaft should not be too hard to rotate with the plugs removed...

cranking with the starter, plugs removed it should crank even if you had a poor connection don,t take much power to crank the engine

could the bendix be stuck up in the gears of the flywheel

Month latter sometimes people never tell us what happened.

could be helpful to someone maybe. i still wonder about those broken studs of mine,see you chief.