4.3 mercruiser grinding noise

[Jvanlue]

Have a 91 Bayliner with a 4.3 mercruiser. Boat ran great last summer. Forgot to take plug out and it rained. Engine compartment flooded including submerged starter. Replaced starter with a new one from db electrical. Tried starting back up and the engine made a horrible grinding sound. Tried starting a second time, it cranked over two times and then just sounds like the new starter is spinning. New starter came with a black shim that I installed. Should I try pulling the shim out and seeing if that helps the flywheel better engage?

 

[alldodge]

I would first remove the drive, it could be the gimbal bearing is rusted and is binding. Being a 1991 the starter should have the offset bolt pattern starter and a shim should not be necessary

 

[Jvanlue]

Ok so I loosened the starter, removed the shim and tightened the starter back up and voila! The grinding stopped and it started cranking. I spent about three minutes trying to get it started, filled it with gas, sprayed some starter fluid in the carberator, and then suddenly I lost all power. No gauges work, nothing clicks. It's like a fuse blew but I can't find it. I've read about blowing the ignition fuse while cranking but I can't find where this fuse is supposed to be. I do have the big red circuit breaker but that isn't tripped.

 

[alldodge]

Look under the helm at the key switch, there are 3 wires on it.
Red/Purple = Battery power from 50 amp breaker via 20 amp fuse
Purple = Ignition power ON
Yellow/Red = Start

Follow the Red/Purple back to a inline 20 amp fuse, may also have a breaker on a panel

 

[Jvanlue]

I have laid on my back for a couple hours, tried tearing apart my panel, and I can't find an inline 20 amp fuse. I'm almost ready to give up and take it in somewhere.

 

[alldodge]

If you have a voltmeter, see if there is 12V on the red/purple wire

If 12V is there then it might be the key switch. Check connections when key is turned

If 12V is not on the red/purple, see if its on both sides of the 50amp breaker on the motor

 

[Jvanlue]

Checked all the wires off the ignition switch and I'm getting nothing on the meter. However I did discover the trim is working fine

 

[Jvanlue]

Checked both sides of the circuit breaker and it's zeroes all around

 

[alldodge]

OK, the you blew the 90 amp fuse. Its on the starter post

 

[Jvanlue]

You're not going to believe this but somehow the main power cord going from the battery to the starter broke off I found the cord hanging today the eyelet broke somehow

 

[Scott Danforth]

most likely corroded.

 

[tank1949]

You're not going to believe this but somehow the main power cord going from the battery to the starter broke off I found the cord hanging today the eyelet broke somehow

Check ALL others for breaks or green corrosion, especially ground connectors. Trust me! Use meter to retest for 12+ volts from helm switch too. I had helm switch circuit breaker go bad and caused starter to drag and it "ate" ring gear. Salt water will find anything in a boat to corrode.