1994 Evinrude 115 Steam from tell tale.

[Throbbin Rods]

Trying to get my buddy's new to him boat ready for when he gets out of the hospital. I have spent a fair bit of time on the carbs, finally all passages are open. New impeller. New spark plugs. Starts right up and sounds great. Today I was making some adjustments to the throttle linkage since the thing was idling at about 1400 RPM and started the motor to watch the tach while setting the linkage.. First time I have run it more than 30 seconds or so. It was peeing out the tell tale just fine on the muffs for a bout 3-4 minutes, then all of a sudden no water, but steam coming from tell tale. Shut off quickly as motor was pretty hot to touch. Could it be that the previous owner put the Thermostat in backwards? I wouldn't be surprised based on other findings so far on this motor. Any thoughts appreciated.
Thanks,
Bill

 

[David Young]

I'm no expert but i 'think' boat motors idle higher on muffs than when in the water. Your thermostat could be bad and worth checking out.

 

[Crosbyman]

impeller key ok ?

 

[emdsapmgr]

Thermostats, plural. One contols the flow of water to each head. If you check the cyl head temps with a laser temp gun you'll get an idea which head is the overheating one. Also, keep in mind that the plastic valve body inside the stat housing has an oval hole between the two center large holes. If that hole gets plugged up for some reason (sand, debris, etc) the powerhead will overheat both heads-even though you have new stats and a new impeller.

 

[emdsapmgr]

This is a pic of the valve body gasket with the hole.
the hole varies somewhat based on the year.

 

[David Young]

impeller key ok ?

This is something i believe i would be checking if i were having a problem like you are. Along with the thermostats

 

[Throbbin Rods]

Thanks for the feedback guys. I appreciate it. I will check the thermostats and if there are no problems there I will pull the lower unit back off and check the key
thanks again!
Bill

 

[Fed]

Were you feeding it enough water at 1400 RPM with the muffs overflowing around the leg?

 

[Throbbin Rods]

Thanks for all the input. I had lowered the idle to around 850 rpm, then I noticed the telltale dying out. Had a nice tight connection with the muffs and tons of water volume and pressure in the hose.

Finally getting back to the motor after fighting the creeping crud for a couple of weeks. Attempted to get the Thermostat housing off yesterday, someone previous had kindly drilled access holes in the lower cowl to access the Thermostat housing bolts. That was the good news. The bad news is that the center bolt won't budge. Not exactly thrilled about breaking it off and having to drill and tap. I am contemplating heating the head of the bolt only, then squirting cold water on it to drive the heat into the threads, repeat as needed. I used this method successfully many times in my career as an auto tech. The housing appears to be some sort of plastic so it will need replacing, but with one hand in a cast this might be my best option. Any other thoughts for removing this bolt?

 

[Throbbin Rods]

Got the bolt out by heating the head and cooling with water. Three cycles did it. I ran a tap down through the hole, blasted some Deep Creep in there and ran the bolt in and out several times. Based on diagrams I have looked at the stats were installed backwards (?) and the stat gaskets (small cork circles) were missing. There was all kinds of gasket sealer in one of the hose nipples, along with pieces of old gasket stuck in the sealer. One stat does not seem to want to open no matter how hard I squeeze. Tomorrow I will heat the stats up in a pot of water on the stove to see if they open. New Thermostat kit is on order.

 

[Fed]

Good work on the bolt, keep the progress reports coming.

FWIW I did some Google checking and found an interesting thing about the small cork circle locations.

The BRP website shows them in different locations to my genuine OMC manual but the t'stat orientation seems the same.





Plus a third from an after market parts website.



Just goes to show you can't believe everything you see on the internet.