1992 Evinrude 150 Oceanpro

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Aug 4, 2002
Messages
58
I recently purchased a 1986 20' Aquasport center console with the 1992 Evinrude 150 Oceanpro on it. I pulled the thermostat caps to see what the t-stats look like after being in salt water and there was no t-stats just a hole where they go. The VRO has been removed and everything bypassed correctly, as far as I can tell from what I know and have learned.
I noticed that the starboard head gets hotter than the port side head. Do the t-stats need be in, what will happen if they are not installed?? I have run it twice so far in the Charleston S.C. bay. At first it was a PITA to start so I checked the plug gaps and they were WAY out, like .040-.045 they are now at .030 and fires right up first crank but runs rough at idle and runs like brand new at WOT. Could this be because of no t-stats? Trying to solve the rough idle situation!!!
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
16,081
I noticed that the starboard head gets hotter than the port side head. Do the t-stats need be in, what will happen if they are not installed??
Runs cold...smokes like a chimney, oil runs out of exhaust ports, fouls plugs and carbons up the combustion chambers. Makes a real mess once water temps get down in the 50's

Running in SW, make sure you get SS thermostats. Mine are 10 years old and still look like new.
and runs like brand new at WOT. Could this be because of no t-stats? Trying to solve the rough idle situation!!!
Rough idle compared to what? Not the smoothest idling motors by any sketch
 

saltchuckmatt

Commander
Joined
Jul 19, 2019
Messages
2,646
I recently purchased a 1986 20' Aquasport center console with the 1992 Evinrude 150 Oceanpro on it. I pulled the thermostat caps to see what the t-stats look like after being in salt water and there was no t-stats just a hole where they go. The VRO has been removed and everything bypassed correctly, as far as I can tell from what I know and have learned.
I noticed that the starboard head gets hotter than the port side head. Do the t-stats need be in, what will happen if they are not installed?? I have run it twice so far in the Charleston S.C. bay. At first it was a PITA to start so I checked the plug gaps and they were WAY out, like .040-.045 they are now at .030 and fires right up first crank but runs rough at idle and runs like brand new at WOT. Could this be because of no t-stats? Trying to solve the rough idle situation!!!
Engine was designed to have t-stats. Perhaps you have some clogged passageways. Do you have any temp readings of each head?

Is your overheat alarm working?
 

racerone

Supreme Mariner
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Dec 28, 2013
Messages
37,829
Trouble shooting starts with a compression test.------Post your numbers.
 
Joined
Aug 4, 2002
Messages
58
Runs cold...smokes like a chimney, oil runs out of exhaust ports, fouls plugs and carbons up the combustion chambers. Makes a real mess once water temps get down in the 50's

Running in SW, make sure you get SS thermostats. Mine are 10 years old and still look like new.

Rough idle compared to what? Not the smoothest idling motors by any sketch
It does smoke till it warms up..

I'll put in the t-stats regardless and yes I'll get the SS ones for sure, thanks for the heads up on that...

I was not sure if rough idle was adherent to these, it doesn't seem to be a problem just wasn't sure if it was normal or not.
 
Joined
Aug 4, 2002
Messages
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Engine was designed to have t-stats. Perhaps you have some clogged passageways. Do you have any temp readings of each head?

Is your overheat alarm working?
overheat alarm is not hooked up. I know it should chirp when the key is turned on which it does not. I have the service manual but the colors don't seem to match up. The buzzer has 2 wires going to one post and nothing on the other post so I need to find that wire. Who ever had it before did a lot of wiring that is atrocious, dead ends everywhere. I've been rewiring everything on it. When I get home I plan on tracing the temp. sensor wires and see where they go. Are they supposed to go to the buzzer or ignition?

I don't have any readings as the temp gauge is not hooked up correctly. The guy had a jumper going to each "S" post on each gauge starting from the fuel gauge.

The wires from the motor are faded and tough to decipher what color is what so I have to trace them one at a time.
 
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I really like this motor, from what I read they are pretty rugged, easy to work on and parts are available...
 

havoc_squad

Senior Chief Petty Officer
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Mar 5, 2011
Messages
738
I need to rent a comp. tester from the parts store. Been wanting to do this but been busy. I'll see if I can get one this afternoon..
Really should buy a decent quality one if you plan on working engines especially outboard often.

$50 from most places in the US will get you a decent one.

Compression and spark gap tester are two key tools even weekend DIYrs need to have.
 

saltchuckmatt

Commander
Joined
Jul 19, 2019
Messages
2,646
overheat alarm is not hooked up. I know it should chirp when the key is turned on which it does not. I have the service manual but the colors don't seem to match up. The buzzer has 2 wires going to one post and nothing on the other post so I need to find that wire. Who ever had it before did a lot of wiring that is atrocious, dead ends everywhere. I've been rewiring everything on it. When I get home I plan on tracing the temp. sensor wires and see where they go. Are they supposed to go to the buzzer or ignition?

I don't have any readings as the temp gauge is not hooked up correctly. The guy had a jumper going to each "S" post on each gauge starting from the fuel gauge.

The wires from the motor are faded and tough to decipher what color is what so I have to trace them one at a time.
Shouldn't run it until alarm is hooked up. With missing t-stats there is a good possibility there was an issue.

Temp sensor comes out of the back of the head....note wire color.

I was thinking of an IR gun like this.
 

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Aug 4, 2002
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Trouble shooting starts with a compression test.------Post your numbers.
Port side from the top 1=92, 2=92, 3=94
Starboard side from the top 1=93, 2=98, 3=98
stayed the same even after I sprayed some lube in each cylinder and retested
 
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Aug 4, 2002
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I'm here in Charleston S.C. for a few months from Idaho doing some work so all my mechanikin tools are there. I really don't want to spend money on stuff I already have at home...
I picked up the bloat knowing it needed some TLC so Break Out Another Thousand it is but I believe well worth it...
After running it for a while, like 1/2 hour on WOT and puttering along I checked the head temp by hand, the port side was warm to hot I could keep my hand on it in different areas, the starboard side was hotter but not to where I could not keep my hand on it so I did not worry to much about it overheating. Knowing this does not have all of the electronic stuff on it the newer ones do I did not know if the carbs had to be at a certain temp to run efficiently. Also I see the rectifier is water cooled, interesting...
 
Joined
Aug 4, 2002
Messages
58
Shouldn't run it until alarm is hooked up. With missing t-stats there is a good possibility there was an issue.

Temp sensor comes out of the back of the head....note wire color.

I was thinking of an IR gun like this.
that was my other option, the temp gun. should one head but warmer than the other?? and what is to hot a temp??
 
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