TOPIC: help with 1960 40 hp johnson carb rebuild

Hello,
My project has been on hold for over a year, but back at it now. Can someone help me with some questions. I am not familiar with any of this stuff, and have never done this before. I am reconditioning a 1960 Johnson 40, and have rebuilt the ignition system with new coils, new points and condensers, and new plug wires. Now I am rebuilding the carb with a Sierra kit. What is the red assembly on the left hand side of the carb in the picture? Is it part of the "Automatic Choke" ? I understand that this didn't work to good. Should this be rebuilt in some way also?

Also, when I disassembled the carb, the instructions state there should have been a washer on the vertical nozzle in the upper carb body but there was not. Should one of the washers in the kit be put on during assembly?


I understand that 1960 was not a good year for the 40, but I have had her running and it run well so have decieded to go ahead and do the work.
Thanks to you all for any help, advice
Mike

The red assembly is a " hot water choke "

---

Water is pumped over a bi-metallic spring.-Actually quite a good set-up but maybe overkill for the people of that era.--Some folks would remove the thermostat and then wonder why there were problems.

Thank you for the info.
To better understand this arrangement , does this mean with the choke lever on top of the carb set at Automatic, the choke butterfly will be closed when engine is cold, and the hot water choke will open the butterfly when water warms from engine heat? So this lever should always be set on Automatic? As you may have guessed, I have not used this boat yet so not yet familiar with it.

I plan on cleaning the carb with this assembly still attached because I don't want to mess with it, is that ok?

Thanks again for the help,
Mike

Your understanding of how the auto choke works is correct...
At this stage in your engine's career, if the auto choke works, &
opens the butterfly "on time", that's great....If not, use the
manual procedure...

I believe that carb cleaner should only be used on the parts where
gasoline flows...I wouldn't "dip" the auto choke part...

I'm curious as to where you got info that 1960 was not "a good year
for the 40"?? (I had to look quite a while to find one)

Ed

Hello Ed,

Thanks for the response. At this point, I don't know if it will work because I haven't had the engine running long enough and it was not pumping water because I failed to realize that the water level had to be over the inlet hole in the leg extention. Time will tell on the choke.

The info on the 1960 Johnson 40 as being one to avoid came from the book "Cheap Outboards" by Max E. Wawrzyniak. It is a great book for a guy like me with no extensive mechanical experience. This book gives very good step by step instructions for tuning up an old OMC outboard; it was just pure luck that it dealt with the exact engine that I have, I didn't know that when I bought the book. He talks about how the 60 and 61 40's are bored out versions of what started out as a 25 hp engine, leaving the lower end a little weak for the extra hp. I don't know.

Hopefully this engine will prove to be alright because it is a good looking engine and looks great on the stern of our 1964 MFG Niagra
Thanks again,
Mike

Water level must be about 6" above the pump.---At this point you might as well inspect the pump as they are easily damaged when run dry !

Professor,
Thanks. Yes, I have a new impeller to put in when I'm done with the top end.

I have another question. I am rebuilding the carb with a Sierra kit. The carb has the brass vertical high speed nozzle in the center of the bowl. It is inserted up into the cast shaft that is part of the upper body. This nozzle had no gasket on it when I removed it nor is there a gasket stuck up in the upper body. The rebuild instructions warn against omiting this gasket during re-assembly but there is no gasket in the kit that will fit up in the shaft. There is a cork donut but it is way too big. I'm confused. I new this would happen. Should it have a gasket or not?
Thanks,
Mike

Mike: Thanks for the "Cheap Outboards" reference....

Sounds like you are doing the research and getting the info inorder to do the job right....

I took note of the 6" over the pump impeller; good to know... Ed

Ed,

The book "Cheap Outboards" is very good, but it can be a little too general for someone who really knows very little about engines; like me! For instance, the carb section is dealing with a carb that is slightly older than the one I have and have found the info to be confusing. I have also learned that I would have been better of with an OMC rebuild kit for the carb, not the Sierra kit that I used that are recommended in the book.

At this point, I have the carb rebuilt, the magneto rebuilt, the fuel pump rebuilt and all back on the engine. The fuel hoses need to be replaced and the new impeller installed.

Thanks for the reply,
Mike