johnson 140 saga continues

T

thebottomfish

Member
Hey everyone, have an 88(thought it was an 89) johnson 140. It runs great, when it runs.
Last week I tracked down some chewed spark plug wires, this week, while jockeying for the boat ramp on the way in I sucked up some mud and grass and whatever other vegetation was floating by. Did not notice I wasn't peeing out of the tell tale. Motor smokes..
Ends up the thermostat housing got so hot it melted the plastic nipple that the cooling hoses run to.
No alarm went off, but I shut her down and roped her into the trailer.
Took it home and found the melted nipples, found a wire causally just stuck in(not connected to) the temperature switch(explains no alarm) so I thought now would be a good time to change the thermostats.
Pulled the housing and there were no thermostats instead I was greeted with, for lack of a better description, globs of dried elmers white glue. I'm attaching some pictures and at a complete loss as to what this can be. It's not salt deposits, I just don't have a clue. Tried to dissolve pieces I chiseled off with paint/lacquer thinner to no avail.
I also assume there is no upside to running without a thermostat, but I'm wondering if there's a reason the p.o. took them out.
So any suggestions whether i should run as is or get thermostats?
Previous owner also used fuel injection hose as the cooling lines any reason I should or should not use that?
Thanks again!
 

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If you got it hot enough to melt those plastic nipples, you have bigger concerns than that crud in the cooling system. I would bet your heads are warped now, and maybe even got the rings if you got it that hot. Not sure what is in there, but it looks like something melted from the cooling system.
 
when you energize the key switch, does the horn beep?
should be able to take the wire going to the temp sensor, touch it to the block and the horn will sound(with the key on).
 
The horn has never beeped from the key being turned to the on position(never knew it should) so I will try grounding that wire tomorrow. Does anyone know if it's the tan wire or the white with black stripe?

The ferminator...what would you do in this situation? Pull the heads?
 
yes, pulling the heads would be 1st on my list if it got that hot. and the tan wire is for the alarm, white with a stripe goes to the powerpack and controls the fast idle.
 
are u running premix or using the injection system? not sure on that motor, but if injecting, should hear a horn on precrank (southern word).
 
I am running premix, previous owner disconnected vro system. I will try grounding the warning horn as well as the compression test this afternoon and I guess I'll proceed from there.
This may seem stupid, but every time I've compression tested I've done it cold, with water running and warm with water running just because the muffs we're going to be on there sooner or later...since I won't be running the motor for this test do I still need to hook it up to muffs?
 
Water optional... You WILL be replacing the impeller RIGHT.. Just go ahead and pull the LU off.

Compression test done at wot with ign disabled.
 
I'd leave the lower unit on until you do the compression test.

No immediate need to get the lower unit off if it has bad compression.
 
Yes I already have the water pump, thermostats, house barb nipples on order, today will determine if I'm getting head gasket as well.
Doing a compression test with the thermostat housing off the block should not effect anything correct? I know it's only 8 bolts but I don't feel the need to put them on to do the test.
Correct me if I'm wrong?
 
Okay guys, compression numbers as follows 120, 118, 113, 118...So to say I'm amazed the numbers match my compression from last week is an understatement.
Now it brings me to a dilemma...do I pull the heads and try to get this gunk out? Unless I put the head gasket on wrong I assume I can't screw up the compression. Just seems like I should let it be, after all I'm not sure this gunk is there from my recent overheat or of it's been there since I've owned it.
Dilemma two, of course I want to put in thermostats but since they weren't in there from the previous owner I'm not sure I should, for testing purposes right now...thoughts?
Warning horn didn't work when the tan wire was grounded and I ran hot lead direct to the warning horn so I think it's the horn that's toast...guess I gotta source one of those.
And I get to try my hand at replacing the water pump which I knew from the get go. Any tips disconnecting it from the linkage?
 
thebottomfish said:
How do you test at WOT? If i move my throttle lever on the control box out of neutral it won't crank
Never knew you were supposed to test at WOT, interesting
Click to expand...

Depending on your controls you should have either a lever to open the throttle at idle or a button that allow the throttle to be opened without putting the engine in gear.
 
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