50 HP Suzuki Overheat

[DaveS]

Yesterday, while cruising in the San Juans, the dash gauge for our starboard 50 HP Johnson (Which is actually a SUZUKI), indicated "Overheat" with the alarm sounding and simultaneously the engine began running rough. I immediately shut it down. Went back to the engine, looked for anything that might have plugged the three water intake screens and tilted the engine as well looking for obstructions. Seeing none, we continued on our cruise on the port engine and after about 15 minutes restarted the starboard engine and everything ran smoothly. After about 30 to 45 minutes the same thing occurred. Prior to shutting down the engine, I looked back and there still was a strong steady stream from the "micturation" hole.

This occurred about 4 more time during our cruise. There was never a problem with the port engine.

Hopefully, someone has some thoughts on what the problem might be.

[Captains Cat]

Dave, sounds like the thermostat may be sticking. I think the water pump will still pump and the telltale hole will still indicate flow if that happens. Hopefully an easy changeout.

Another reason for twins!

Charlie

[Hunkydory]

Dave

I'll second Charlie's opinion on stuck thermostat. One of ours stuck open on the Honda 40 and created cold engine and rich burn with gas going into engine oil. Was a puzzler until Les at EQ told me what the problem was. Changing thermostat on the Honda was very easy and just a few minutes job.

And yes Charlie with the twins made the run from Juneau to Skagway, but it was only at about 8 mph or less.

Jay

[DaveS]

Thanks guys! We discussed the possibility of a stinking thermostat.

(I meant "sticky" but it was a typo or perhaps a freudian slip? So, I just left the above comment as it appeared when I proof read it).

[Sealife]

Definetly sounds like a sticky thermostat. I've got twin 50hp Suzuki's and my port engine, after 430 hours, overheated in the same manner. Turned out to be the thermostat. They sit right on top of the engine...very easy to replace. Replaced both port and starboard, which cured the problem in the port engine, preventive maintenance for the starboard. Plus, I bought a spare.

[DaveS]

It took me less time to remove and insert the new thermostats in both engines than it took me to call up on the telephone and locate the thermostats. Initially, I called Bayside Marine in Everett (a Johnson dealer) but they would have had to order them and would not have had them until the beginning of next week. They suggested that I call Performance Marine in Everett (a Suzuki dealer), which I did. They had them on stock and I drove there and purchased them. I'll now go back and purchase a spare to put on the boat (along with all the other spare parts I carry), should I have similar problems in the future. (I guess this is a plus factor for owning a Johnson that is really a Suzuki therefore I guess could be called transgender or something like that, so there is more than one dealer that can be of service to your engine.... ).

While I was messing around on the boat, I also pulled the props, re-lubed the shafts, and then changed the fuel/water seperator. (Only a few minute particulates and no water). My Marine Stabil seems to be successfully combating any concerns with the 10% ethanol fuel that I use.... .

Thank you again, Charlie, Jay and Mike for your prompt answers regarding the problem. You guys as well as the other C-Brats are a much better resource than any outboard maintenance manual that I've seen!

[Captains Cat]

I, and I'm sure the other Brats will take the Kudos when it's fixed! Hopefully soon, please let us know!

Charlie

[Robbi]

Dave, I am so glad that you got in touch with Performance Marine. If anyone has an issue with a Suzuki, get a hold of Doug. He knows his stuff!!!

Robbi

[DaveS]

Now for the rest of the story......YES! The problem was definitely the thermostat. We just returned form a six day cruise and experience nary an engine problem.

Thank you all for your input and rapid correct diagnosis!