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1979 Evinrude 140 Thermostat Replacement

S

smhamilt

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"Having a heck of a time with

"Having a heck of a time with installation. WHAT IS THE TRICK????? springs compressed into the valve body, thermostats in place and then having enough room to place the thermostat cover between the exhaust cover and the rear motor cover. Do you have to remove heads or exhaust cover to get this in???? Or do I need to grow smaller fingers? THANKS A MILLION FOR YOUR HELP"
 
"powerheasd removed,or exhaust

"powerheasd removed,or exhaust bubble removed,is best...i have done em,by loosening the lower pan ,dropping it down some too,no matter how u do it,w/the 2 things on above,its tough."
 
"Thanks. Got it done but i th

"Thanks. Got it done but i think I overtightened the portside bolt. May have lost those threads. No leaks no overheat...no problem????????

Also, on the exhaust house where cooling water exits there are two holes. Just below the lower motor cover. Should water come out of BOTH these holes? When I started motor water exited only from the starboard side then water wasnt coming out of either hole but out of the lower unit. Is this correct?"
 
"(Exhaust Relief Ports - E

"(Exhaust Relief Ports - Exhaust Housing (Inner/Outer)
(J Reeves)

The long housing between the powerhead and the lower unit is called the exhaust housing. There is a inner housing within it that has a heavy duty seal around the bottom of it, or heavy duty seals around a inner extension between the housing and the lower unit.

The red hot exhaust travels down thru that inner tube and out the propeller with a somewhat supply of water to cool the propeller hub. A good amount of water surrounds and fills the space between the outer and inner tube, otherwise the outer housing would get so hot that the paint would burn off.

Some water pumps, for some reason (differing even when new) exert a great amount of water pressure, and if the exhaust housing seals are in perfect condition, the water fills the tube to a point of overflowing.

This brings into play those two holes or slots, whichever the engine might have, at the top rear portion of the exhaust housing just below the powerhead.

Now, if those two holes/slots weren't there, water would continue to flow up into the cylinders. Water not flowing out of those holes is no concern for alarm UNLESS that outer housing suddenly becomes extremely hot..... the warning horn should sound long before that happens.

The main reason for those holes being there (exhaust relief holes) is that when at an idle, there is an extreme amount of resistance encountered by the exhaust trying to escape due the fact that the outlet via the propeller is now blocked by a wall of water. The escape route in this case is for the exhaust to escape out those two holes, otherwise the engine would slow down quite quickly and die. If exhaust cannot escape, air/fuel cannot gain entrance to the engine.

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay store at:

http://stores.ebay.com/Evinrude-Johnson-Outboard-Parts-etc?refid=store"
 
"A trick we used with your mod

"A trick we used with your model was to use adhesive M made by omc and assemble the thermo block together and hold in a vice until the adhesive had dried , because it was stuck together it didnt fall apart when you fitted it back on the engine.

You will notice once the thermo's open water exiting from the holes above the rear section of the cav plate. The bypass valves when working will dump water out the relief holes just under the rear section of the lower cowl...it is not abnormal to see a bit dribble out from time to time at idle."
 
"I used to tie the parts up wi

"I used to tie the parts up with 2 Tie-Strips until I got all the screws entered and loosely tightened. Never had any problem with that method.
Water will get out of the relief holes as the thermostats open and close on idle, and when relief valves opens at higher rpm's. If only out from one hole at idle, might indicate a faulty thermostat. Remember to change thermostats in pair!"
 
I used a combination of adhesi

I used a combination of adhesive (Jamie) for sealing purposes and the tie straps (Morton) on those assemblies when installing. Otherwise parts went a flying!
 
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