Non Starting Mercruiser 120

[filmmaker101]

Its been a couple of years since I have last seen the water, and now I have some time and wanted to get back out there.

Only problem is, I cannot get my engine to turn over.

I went through the seloc manual and followed the directions on troubleshooting starting conditions but the information didnt cover my malfunction or correction.

I turn the key, i get a click in the starter relay.

If i use a screwdriver to jump the starter relay, the starter kicks in and clicks loudly but doesnt turn the motor over.

any and all help would be certainly appreciated.

-michael

 

[Bt Doctur]

Re: Non Starting Mercruiser 120

Was it winterized properly? Is the engine oil at "full" or above?
Condition of the outdrive oil?
Pull the drive to isolate the problem, still womt turn, pull the plugs and probe with a wood dowel.rust deposits would indicate water intrusion and maybe a seized motor

 

[inspectorjones]

Re: Non Starting Mercruiser 120

I had the same Exact problem, I tore the starter apart and found that it was severely corroded, to the point it had to be replaced. The springs for the brushes were frozen so it wasn't making good contact. Long story short I had to but a new starter.

Mike

 

[filmmaker101]

Re: Non Starting Mercruiser 120

Is there a way to manually turn over my motor to see if it is seized?

 

[JoLlY_RoGeR_ARRRR!!!!]

Re: Non Starting Mercruiser 120

Is there a way to manually turn over my motor to see if it is seized?

Pull the spark plugs, get a socket to match what is on your balancer get a ratchet and turn in the direction the engine turns. Might be a good idea to dab some oil down the cylinders since it has not been ran in a few years.

 

[Bt Doctur]

Re: Non Starting Mercruiser 120

Most crank nose bolts are 7/16ths,think about that turning a motor over.
Snap the bolt and your done. PULL THE DRIVE FIRST,CHECK THE OIL IN THE DRIVE FIRST.remove the starter and try with a large screwdriver or crowbar.
come back with the test results

 

[Bondo]

Re: Non Starting Mercruiser 120

CHECK THE OIL IN THE DRIVE FIRST, PULL THE DRIVE, remove the starter and try with a large screwdriver or crowbar.

Ayuh,... The 120hp has the front motor mount, Tight to the front pulley...

Do as noted by BD,...
Test sample of oil from the drive,..
Remove the drive,+ the Sparkplugs,..
Then turn it with a bar against the flywheel teeth, or possibly a big strap wrench on a pulley....

Of course,... If you get Chunks in the outdrive oil sample,...
It's probably the Drive that's the Problem, but you should try spinnin' the motor anyways...

 

[filmmaker101]

Re: Non Starting Mercruiser 120

i checked the oil and its pristine. just borrowed a chain wrench to try to turn the motor over but im not sure if it turns clockwise or counterclockwise if standing in front of the motor, facing the outdrive.

any help on which direction the motor turns?

thank you!

michael

 

[marlboro180]

Re: Non Starting Mercruiser 120

i checked the oil and its pristine. just borrowed a chain wrench to try to turn the motor over but im not sure if it turns clockwise or counterclockwise if standing in front of the motor, facing the outdrive.

any help on which direction the motor turns?

thank you!

michael

If you are facing the stern from in front of the engine inside the boat, turn it clockwise if you want it to go the direction it does while running. Got some oil down those spark plug holes????Negative terminal detached???Ignition off??

 

[filmmaker101]

Re: Non Starting Mercruiser 120

If you are facing the stern from in front of the engine inside the boat, turn it clockwise if you want it to go the direction it does while running. Got some oil down those spark plug holes????Negative terminal detached???Ignition off??

perfect information, and yes, i did drizzle some oil down the plug holes into the cylinders and did disconnect the battery.

I will let you know in a bit what the results were.

thank you,

michael

 

[filmmaker101]

Re: Non Starting Mercruiser 120

i put a screwdriver on the top end and it turned rather easily but the i didn't see the crank belt housing turning with it and while looking closer at it, there is no way in hell i will be able to get a chain around that belt housing to turn the crank over manually the motor mount is directly above the belt housing and into the motor.

ahhh, more disappointment.

i will pull the starter and have it tested and start from there. pulling the motor is the last thing i really want to do, but if i must, i must.

 

[filmmaker101]

Re: Non Starting Mercruiser 120

i didn't realize that the top end turning doesn't mean a thing as its the water pump. oops.

anyhow, i removed the starter and took it to my local service center and it was not just froze up but it was super frozen.

another $200 toward the good of all evil.

the mechanic gave me some good advice on turning over the motor.

i was advised to put the motor in forward gear and to step on the propeller. if it turns, the motor is not frozen, if not, it may mean that there are deeper malfunctions with the motor.

i flew home, threw the starter on to the couch and ran into the garage and on to the boat.

i slammed the drive into forward and jumped feet first over the stern. i stepped gently onto the propeller and it did not turn.

oh my, the tears drained me immediately.

i now have the plugs out and soaked the cylinder heads with a deep penetrating oil.

we shall see if that helps to loosen it.

I'm no longer optimistic about saving the drive, but anything could happen.

any other ideas?

 

[Bondo]

Re: Non Starting Mercruiser 120

any other ideas?

Ayuh,... Pull the Drive....
Then you'll know whether you're fighting a Motor problem or Drive problem...

 

[Don S]

Re: Non Starting Mercruiser 120

i was advised to put the motor in forward gear and to step on the propeller. if it turns, the motor is not frozen, if not, it may mean that there are deeper malfunctions with the motor.

That's not a test, that's a "Get out of my face, I have work to do for a paying customer" answer.
I've stood on props before to prove a point. The engine didn't turn when I jumped on it. Then I hit the key and it started immediately.

 

[filmmaker101]

Re: Non Starting Mercruiser 120

That's not a test, that's a "Get out of my face, I have work to do for a paying customer" answer.
I've stood on props before to prove a point. The engine didn't turn when I jumped on it. Then I hit the key and it started immediately.

I just didnt want to put in the new starter and ruin it by trying to turn over the motor and then to find out that my motor is froze and now my new starter is shot too.

i will attach the starter and give the key a quicky to see what happens.

i thought of doing that yesterday but the mechanic advised me not to, as its a step-down starter and will quickly ruin it if the motor is frozen.

i will return with results.

 

[Don S]

Re: Non Starting Mercruiser 120

If you have the starter off, just use a screwdriver to bar the engine over using the teeth on the flywheel.

 

[filmmaker101]

Re: Non Starting Mercruiser 120

i don't understand how to use a screwdriver on the teeth of the flywheel to turn the motor over.

if ya didn't know, im a pretty big boy, it was quite a workout just to get the starter off.

 

[Bondo]

Re: Non Starting Mercruiser 120

i don't understand how to use a screwdriver on the teeth of the flywheel to turn the motor over.

Ayuh,...

The Flywheel is exposed when the starter is removed....
Use a Big screwdriver or other Prybar,+ engage a tooth on the flywheel,+ pry against whatever works for you...
You should be able to rotate the motor about 1? either way, per tooth....

Pull the Drive....
Then you'll know whether you're fighting a Motor problem or Drive problem...

Just in case you happened to miss that comment....

 

[filmmaker101]

Re: Non Starting Mercruiser 120

i keep fighting the notion of pulling the motor unless that is the only solution left undiscovered.

i will try turning with a screwdriver and report my findings.

 

[Bondo]

Re: Non Starting Mercruiser 120

i keep fighting the notion of pulling the motor unless that is the only solution left undiscovered.

Ayuh,..... The Drive,.... Not the motor,.. the Drive.... It's 8 Nuts,+ it's Off....