Freeze Plugs on Mercruiser & Starting Problems

TresGatos

Cadet
Joined
Jun 14, 2004
Messages
11
Inboard twin gas 350 Mercs (1998 MAG MPI). Couldn't start starboard engine. Lots of troubleshooting... starter motor spun, volts OK but solenoid would not engage. Electric, solenoid relay, batteries, connections all perfect. Mechanic said must be bad starter/solenoid. OK, replaced, worked great for about a month, then starting problems again... ARGGH!! Very frustrating ...lots of head scratching...decided to pull new starter and WHOAA..lots of coolant gunk...to make a long story short it turns out one or more freeze plugs on the rear of the block are going bad and the coolant collected in the bell housing which then caused the flywheel to throw it up into the starter...bottom line - need to drop tranny and pull engine to get access to replace a $1.00 part...there goes my tax refund...out of curiosity anyone else had these kinds of problems with Mercs?<br /><br />TresGatos
 

fendersfender

Petty Officer 1st Class
Joined
Mar 23, 2005
Messages
317
Re: Freeze Plugs on Mercruiser & Starting Problems

what do you mean "going bad"...are they pushed out or are they rotten...if they are pushed out, its from freezing...and if they are rotten, they are not correct freeze plugs...marine engines should have brass freeze plugs....unless the engines were rebuilt or replaced with standard freeze plugs...i would check both engines
 

TresGatos

Cadet
Joined
Jun 14, 2004
Messages
11
Re: Freeze Plugs on Mercruiser & Starting Problems

fendersender,<br />The plugs are rotten, not pushed out as I am in San Diego, the only freezing is at the local 7-11. These are the original merc engines with brass freeze plugs, hard to believe. <br /><br />TresGatos
 
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