help identifying neptune

[opposedtwin]

can’t really tell from the old outboard book what this model is. anybody know the proper spark plug for this one? any info you can provide will be appreciated. model is 10 A 4
thanks!
scott

[RICHARD A. WHITE]

1940 4 hp, not the Master, those were monster 16 horsepower motors..Use J6J plug gapped at .025, look on page 299 of the Old Outboard book, bottom left hand side of page… Page 293 has your motor listed

http://www.richardsoutboardtools.com
classicomctools@gmail.com

[RICHARD A. WHITE]

I can get you a photo of one of my 2 Mastertwins, they are pretty good sized motors….If you want

http://www.richardsoutboardtools.com
classicomctools@gmail.com

[kees]

the Old Outboard book gives us not so much info about these engines.
page 282 is a mix of Muncie, Waterwitch, Motorgo and Caille Motorgo.
Do you see model 10 A 4 ? NO. 😕
Neptune / Muncie on page 287 starts with year 1945 and up,
but no model 10 A 4 . 😕
So I took a look in an old "year model guide" what I have from the AOMCI ( bought that years ago )
and what Richard already said ;
It is 4 hp from 1940
but,.. it has also a name !!!!!!!!!!
………….NEPTUNE JUNIOR TWIN…………
that info was missing , now you have it all ( I guess )
😉
.

[RICHARD A. WHITE]

quote kees:

the Old Outboard book gives us not so much info about these engines.
page 282 is a mix of Muncie, Waterwitch, Motorgo and Caille Motorgo.
Do you see model 10 A 4 ? NO. 😕
Neptune / Muncie on page 287 starts with year 1945 and up,
but no model 10 A 4 . 😕
So I took a look in an old "year model guide" what I have from the AOMCI ( bought that years ago )
and what Richard already said ;
It is 4 hp from 1940
but,.. it has also a name !!!!!!!!!!
………….NEPTUNE JUNIOR TWIN…………
that info was missing , now you have it all ( I guess )
😉
.

Sorry for the typo, page 293 has the 10A4 listed,,,sorry guys

http://www.richardsoutboardtools.com
classicomctools@gmail.com

[kees]

Sorry for the typo, page 293 has the 10A4 listed,,,sorry guys[/quote]

I have my senior moments too, and I am sure they will increase when I get older 😆 😆
have fun Richard !
😉

[slim60]

Looks like my 1941 #11B4. I replaced a piston and both ring sets. Compression is 80 and 75 psi with good spark. It will sputter in water without prop but thats all. Today I removed the exhaust with no change. Should I remove the lower unit to decrease the drag more? Doug Penn found parts and a diagram for me. Good luck with your 10A4.

[Author]

Posts