Mercruiser died on water

[LI Bill]

Hello, I'm new to the forums and new to boating, I have been reading through all the good information however. The boat is a 1988 Renken 22ft cruiser with a 5.7 mercruiser. I bought it back in October and spent the winter doing a cosmetic restoration on it. Went for a short cruise last weekend and while underway it stalled out but restarted right away. Yesterday went out with a friend for a short cruise to get some lessons on navigating and docking but didn't get far from the dock when it stalled again but would not restart. Towed back to marina by Seatow. Tested for spark from the coil and got nothing. Put a spare coil in and engine fired right away. Just to double check we put the orginal coil back in and it started again. Any ideas? Bad wiring somewhere? Thanks for your ideas...

 

[Don S]

Re: Mercruiser died on water

Start checking connections in the ignition system. Especially the connections from the distributor to the ignition module. Corrosion can cause your problem.

 

[LI Bill]

Re: Mercruiser died on water

Thank you for such a fast response Don. Is there a recommended or approved method of checking and cleaning connections and should the connections be treated with something to prevent future corrosion?

 

[Don S]

Re: Mercruiser died on water

I take them apart and look. If they are corroded, I replace them.<br />If the problem is the plug on the ignition module, most of the time the pins in the module are corroded all most all they way off. Only thing you can do is replace them. <br />I put dialectric grease on the connections.

 

[I/O WALDO]

Re: Mercruiser died on water

Can try the "wiggle test"for elec.conn. problems.With water supplied to the engine,start the beast(if it will!)& while idling,"wiggle"each of the connectors on the engine and sea if you can create a failure.

 

[LI Bill]

Re: Mercruiser died on water

Thank you again Dan and Waldo, I'll do some trouble shooting and cleaning this afternoon and see what happens...

 

[KRS]

Re: Mercruiser died on water

I know it's not the problem here, but a fuel filter and separator change would be a good idea if you haven't done it yet.

 

[LI Bill]

Re: Mercruiser died on water

An update, I spent a couple of hours down at the boat yesterday cleaning/inspecting/sealing electrical connections, which looked long overdue anyway...didn't see any glaring problems however. Connector from the distributor to the ignition module didn't look too bad, very slight corrosion on the pins, but the pins themselves looked intact. I know anything can fail, but can the ignition module fail intermittently, or does it generally totally fail? Is there anyway to check the module to see if it is functioning properly...I dont mind buying parts, but I hate to throw money at something that may not be the problem. KRS, I changed out all the filters. Thanks for the help guys...

 

[Bt Doctur]

Re: Mercruiser died on water

cannon plug at engine, inline ign. fuse under dash, tach going bad.when it goes dead ,do the gauges still read?

 

[LI Bill]

Re: Mercruiser died on water

Bt Doctur, thanks for the reply. i have alot of experience with cars, but almost none with boats. Id the cannon plug the main plug on the starbaord side? It seemed to not be pushed in all the way when i removed it yesterday. I did remove it and applied diaelectric grease when I reinstalled. Question regarding plug, is there some kind of clamp on it which insures a position conection? If there is it seems to be missing. Gauges still work when engine stalls, and the tach is new. I will check under dash to see condition of wires and connections. Someone mentioned streched shifter cable could cause problem. Sound logical? Thank you for the advice.

 

[I/O WALDO]

Re: Mercruiser died on water

Did you "wiggle test"?

 

[LI Bill]

Re: Mercruiser died on water

Hi Waldo, no not yet, I decided to try and spend some time removing and cleaning connections yesterday until I ran out of daylight. I thought it wouldn't hurt to check connections first before I started it up and got it hot. I will reassemble everything today and "wiggle" test. Weird thing is that it runs fine at the dock, only stalls when under way. I'm still thinking loose connection someplace, but my confidance to take it out for a test run is low.

 

[Bt Doctur]

Re: Mercruiser died on water

a hose clamp on the canon plug works.<br />still could be the tach.

 

[LI Bill]

Re: Mercruiser died on water

Update: Spent a few more hours yesterday afternoon cleaning/inspecting/sealing wire connections. Changed out the cap/rotor/coil, just to make sure they are fresh. Found some really "nasty" looking connections at the starter switch, fairly corroded, and one fairly loose. Engine fired right up at the dock and ran fine (which it always had, only dies out on water). Ran it about 30 minutes while I did "wiggle" test on everything I could see, but couldn't get it to die. So, I guess it's time for another test run? I'll keep the Seatow number handy. Thanks to all who responded