Mercury 40 4HP Overheating

Adamcsincs

New Member
Joined
27 Apr 2007
Messages
1
Visit site
I recently bought a old 1969 mercury 40 4hp outboard. Noticing that there was no water coming out of the pee hole, only hot air, I took apart the water pump and the impeller looked fine. Removing the clean water flushout bolt on the lower rear of the motor and running the motor in a tank, water will circulate out the flushout hole. Does anyone know if this motor has a thermostat? Or any ideas for getting the water to come out of the pee hole? I assume something is plugged up but not sure where to look or how to get it unplugged.
Thanks
 
I've had that problem with my mid 80's Suzuki 40hp.

Put a new impeller in anyhow then start the engine (using something to supply cooling water - muffs, running in a tank, etc - then blow compressed air up the pee hole while its running. This fixed mine.
 
[ QUOTE ]
I recently bought a old 1969 mercury 40 4hp outboard. this motor has a thermostat?
Thanks

[/ QUOTE ] I have two 1999 Mercrap engines and had to take out the thermostats. NB I live in the Caribbean.
I am very surprised that a 1969 mercury outboard is working 38 years later. Stillin original packing and never used?
Get a manual [ if you can eg http://www.technicalbooks.co.nz/index.ph...agestyle=single ] and check if it has a thermostat. If it has one it is likely to have a cover on the rear of the block.
 
I cant help with Mercury engines but a good place for help and advice with most makes are the iBoats forums there is a board dedicated to Mercury and Mariner engines. If you do go there quote the full model details (Make, hp, model number and year) with your query.

I have a note of this site as a source of downloadable manuals for Mercury and Mariner engines
 
I recently bought a old 1969 mercury 40 4hp outboard. Noticing that there was no water coming out of the pee hole, only hot air, I took apart the water pump and the impeller looked fine. Removing the clean water flushout bolt on the lower rear of the motor and running the motor in a tank, water will circulate out the flushout hole. Does anyone know if this motor has a thermostat? Or any ideas for getting the water to come out of the pee hole? I assume something is plugged up but not sure where to look or how to get it unplugged.
Thanks



I have the same motor where is the pee hole located at
 
I have the same motor where is the pee hole located at

You are adding to a 9 + year old thread. You would do better to start your own new topic. Adamcsincs has not used the forums since his original post 9 years ago!

However see your owners manual.

If you have mislaid your copy you should be able to download one from http://download.brunswick-marine.com/download

and you will find the diagram below

40%20hp%20merc.jpg
 
Last edited:
Top