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Old 1967 Johnson 3hp motor

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Dan Heerts

New member
HEy guys. Just picked up a really nice 1965 Grumman Sport boat that came with a little (67?) 3hp Johnson. Both are painted in Camo, so the text or "instructions" around the various knobs are not visible. Anyone know if there is some documentation out there for this little engine? I KNOW the throttle lever and pull start is obviou. bu there are 3 other little knobs on the face that I have no clue what they do. Also, what gas/oil ratio should I use in it???

If anyone has more info on these, I'd love some. I am going to post a couple photos here so you can see.

motor.jpgboat.jpg
 
The small lever that can be pulled/pushed if the choke (pulled/choke on-- pushed in/choke off).

The top knob is the slow speed adjustabe needle valve. The bottom knob is the high speed adjustable needle valve.

Fuel oil ratio is 25/1 -- 1 guart of 50/1 oil to 6 gallons of gasoline. 87 octane will be fine.
 
WOW..thanks for the speedy reply. DO you know WHERE I can find the serial and/or model number on this? I know the service manuals are available for these, but I need to first confirm the year and serial number. I am hoping it's somewhere inside, where there ISN"T paint.

THanks
Dan
 
There should be a small plate attached to the port (left) transom bracket, also possibly a small quarter sized core plug (looks like a small freeze out plug) on the powerhead area. Either would have the model and serial number (usually).
 
A white motor that was painted camo ?----Or was the lower unit already painted green ?------Post a picture showing lower unit / midsection.
 
Guys..thanks for ALL of your input. I found the little "plate" that had model and serial number, and you are right. It is OLD than the mid 60's..it is a 1957 engine. MODEL JW-13 and Serial number: 1574480

I'll post a photo of the lower unit and midsection in a bit.
 
WOW..thanks for the great responses. I have not started it up..It was just "tuned" up last season by a boat shop according to the original owner. So I am going to go get some gas, and fire it up today and see how she runs.

No my question on gas. I do use "REC" fuel (90 octane with no ethanol) in ALL of my small engines around the house. Would it be good to run this in this boat motor too? Or would the cheaper 87 octane with 10% ethanol be fine? I don't want to gum up or varnish up the carb or engine. Should I maybe run some seafoam through the engine to clean out anything that may be building up already?

Thanks
 
Well, what can I say. Curiosity got the best of me. I filled up a garbage can with water, put the motor bottom into it, and put about 2 cups of gas in the gas tank. Took all of 6 pulls to start the engine up. I feel it would have started sooner, but I forgot to turn the gas on, the first 3 pulls!! ha ha ha.

Man...this thing runs like a top! I cannot believe how smooth it runs. I checked for water pump function and sure enough water was SHOOTING out good and strong on the back side of the shaft, about half way up.

I ran it up to full power and down to idle until it would die. Runs nice and smooth at full throttle, with the High Speed adjust knob at about 12 o clock...For low idle, I can idle down to just left of the word "start" about an inch, any lower and she dies. Any thoughts on that???

Dan
 
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