1989 Mercruiser starter diagnostics help request

[IGeeky1]

Starter wouldn't start the boat with a good battery so I removed from boat.
Brushes were pretty worn so I replaced them.
Replaced with new starter solenoid.

It still will not start.
When turning the key I get a loud click. I am assuming it is the solenoid throwing out the bendix.
No starter motor turn sound however.

Now if I jump across slave solenoid I get what I assume is the same solenoid throwing the bendix out sound, still no motor spin.

However if I jump from solenoid power post to starter motor power post the starter motor does turn (of course without the bendix being thrown out)

So it seems to me like the starter motor is OK, it just isn't being fed power across the solenoid for some reason? But what?

Thanks

 

[Bondo]

Re: 1989 Mercruiser starter diagnostics help request

Starter wouldn't start the boat with a good battery so I removed from boat.
Brushes were pretty worn so I replaced them.
Replaced with new starter solenoid.

It still will not start.
When turning the key I get a loud click. I am assuming it is the solenoid throwing out the bendix.
No starter motor turn sound however.

Now if I jump across slave solenoid I get what I assume is the same solenoid throwing the bendix out sound, still no motor spin.

However if I jump from solenoid power post to starter motor power post the starter motor does turn (of course without the bendix being thrown out)

So it seems to me like the starter motor is OK, it just isn't being fed power across the solenoid for some reason? But what?

Thanks

Ayuh,.... Welcome Aboard,.... Pull the spark plugs, 'n see if the motor will turn over,...

If it still don't, pull the drive off, 'n try it....

Did ya bench test the starter when ya had it out,..?? sounds like it's Workin',...

 

[Don S]

Re: 1989 Mercruiser starter diagnostics help request

A loud click (sometimes called a heavy clunk) usually means the starter is trying to work, but the engine won't turn over. Could be water in the cylinders, locked up outdrive, blown engine. Hard to say.

As Bondo says, pull the plugs, then the drive, if no turn, see if you can turn the engine by hand. Maybe pull the starter and bar the flywheel over using a big screwdriver on the flywheel ring gear.

 

[IGeeky1]

Re: 1989 Mercruiser starter diagnostics help request

Ayuh,.... Welcome Aboard,.... Pull the spark plugs, 'n see if the motor will turn over,...

If it still don't, pull the drive off, 'n try it....

Did ya bench test the starter when ya had it out,..?? sounds like it's Workin',...

Ooh good point...
It would fit the scenario where the starter would run when the bendix was not thrown out and yet not run when the bendix was thrown out if the flywheel was bound for some reason. Will check tomorrow, thanks.

I wan't sure how to test by using the solenoid but by connecting power to power tab on starter and ground to the casing it turned well and smooth.

 

[IGeeky1]

Re: 1989 Mercruiser starter diagnostics help request

Yeah... so I couldn't get it to turn over with plugs out either. I put a strap on the main pulley and tried to advance the engine that way. No go. So I guess it is time to take off the stern drive this weekend.

Some history. This had been my dad's boat. Two years ago it became mine. First year i had it my brother had a truck so he towed, ran fine. Long story short I ended up not having a vehicle to take it out last year, but thought I did so I got it all ready in spring.

So last year in spring I had it running but it never made it to water. Last fall I tried to start it up to prep it for winter and got the same results I have now. It was late so I concentrated more on alternative winterizing methods than repair.

So it seems it froze some time between spring and fall of last year. Does that help in anybody's guess for what to look for? Figured I throw that out just in case it did. My guess is that if it doesn't spin with stern off that next step it to remove cylinder head...

Thanks

Mark