Overheated today. Now running rough. Where to start?

[shopboy]

Mercruiser 228 1979


In water running great today when temp started rising above 180.

Came off plane and idled to a safe place before engine died. Temp reached 200.


Overheat was caused by a tear in the main hose from the circ pump to the tsat. pouring all the water into bilge.

After a cooling off, and patching the hose with hose clamps, rubber, zip ties etc and removing tstat I was able to restart the engine and idle back to the marina at temp of 145.

On the trip back it ran really rough and died multiple times and had a few small backfires when attempting to restart. . I was able to restart it each time with lots of pumping and wide open throttle. On a couple occasions it seemed to spring back to normal for a few seconds before running rough again...

Getting a new hose asap..

Any advice on where else to check to make sure I haven't roasted anything. My suspicion was that the extra hot coil was causing the rough running . Engine oil is clean with no apparent water in it. Fuel is good.

Thanks


Mike

 

[Bondo]

Re: Overheated today. Now running rough. Where to start?

Mercruiser 228 1979


In water running great today when temp started rising above 180.

Came off plane and idled to a safe place before engine died. Temp reached 200.


Overheat was caused by a tear in the main hose from the circ pump to the tsat. pouring all the water into bilge.

After a cooling off, and patching the hose with hose clamps, rubber, zip ties etc and removing tstat I was able to restart the engine and idle back to the marina at temp of 145.

On the trip back it ran really rough and died multiple times and had a few small backfires when attempting to restart. . I was able to restart it each time with lots of pumping and wide open throttle. On a couple occasions it seemed to spring back to normal for a few seconds before running rough again...

Getting a new hose asap..

Any advice on where else to check to make sure I haven't roasted anything. My suspicion was that the extra hot coil was causing the rough running . Engine oil is clean with no apparent water in it. Fuel is good.

Thanks


Mike

Ayuh,.... How 'bout a real Tune up,..?? Changed the points this year,..??

In my experience, a coil either works,..... or it don't....

Was water sprayin' about,..??

 

[shopboy]

Re: Overheated today. Now running rough. Where to start?

Yep, water was spraying pretty bad but it was high and dry on the top of the motor where the dist/coil is.
It was starting and idling perfectly until after it got hot so I'm pretty confident that the ignition system was in good working order before the heat up.

It has an aftermarket electronic ignition.... I know there are lots of naysayers about that, but I've never had a problem with it.

Thanks for the response ...

Once the new hose arrives, I will see how it runs, and check the cap/rotor and plugs I guess.