Outboard Evinrude Thermostat

[topofthemt]

I recently replaced the impeller on my 1999 6HP outboard engine (long shaft if that matters to anyone), and I swapped out the replaceable parts of the thermostat while I was at it.

Today I did an engine run for a while at the dock (about 25 minutes), it seemed to be running like a champ, but when I touched the water from the indicator, it was very cool. Much cooler than I was expecting, as in, sea-temperature. I probably put the pieces of the thermostat back together in the wrong order, so now I suspect that the thermostat is bypassing the engine and just spitting out cold water? I can't seem to find a decent diagram anywhere that I could use to verify that I've done the job right...any ideas?

Jerrett
Hampton Roads, Virginia

 

[Fly_H23]

Unless you will be running it in cold water, winter temperatures you may not need a T-stat at all. My merc 9.9 list it as an option for cold weather use.

 

[anchorclanker]

It needs the thermostat. Engines without have restricted passages that slow the flow enough for the water to heat up. If you take the T stat out the motor will run colder than designed and will wear rapidly.

Just flip the T stat around, your probably correct that you put it in backwards.

 

[kloudie1]

These guys have a good exploded engine diagram that you can click on to zoom and see how the parts go into the thermostat housing..
http://www.crowleymarine.com/johnson-evinrude/parts/53243.cfm

 

[topofthemt]

Thanks for the tips. Actually, that exploded diagram has been very useful, saw it on the evinrude homepage, however it doesn't seem to exactly match my engine! I'm wondering about the "missing part", that large spacer #41 which I don't seem to have (and I don't think there's room for one anyway). Plus, my engine has a small washer which isn't shown on the diagram. It seems to fit underneath the thermostat #10, but I can't be certain since I'm no expert. Little bit confused here.

 

[kloudie1]

Jerrett.. someone may have messed with the thermostat system before you got it?? It looks like the spacer keeps water from bypassing the thermostat which would give the symptoms you are seeing, I think.. Check the assembly sequence as well.. thermostat underneath the diaphragm and cup assembly .. springs 13 and 43 in correct locations, thermostat housing (59) correctly seated .. If it still looks strange, verify the model number is the one you have.. ??

Edit
Yours is a single cylinder four stroke? not a twin two stroke (1998) correct..??

 

[topofthemt]

Its a signel cylinder, 4-stroke. If that spacer is missing, uh oh. I guess I wouldn't be surprised, the previous owner told me how he likes to keep the thermostat real clean, regularly, and how he has to be careful about loosing all the loose parts in the water. Maybe he lost one of the parts. Everything else seems to be in order...but if there really is supposed to be a spacer in there, I can't fathom how it will all fit! Its pretty jam packed already. Time to put in another parts order I guess...