Neptune Outboard Motors

Neptune   Model Year Guide

1930 - 1940

(All models made by Muncie Gear Works)

Model	Serial	Description	HP	Cyl	Notes
		1930
OB2		Muncie Twin	2.5	2
OB2A		Neptune Twin	2.5	2
		1931
OB2A		Junior Neptune	2.5	2
OB2CB		Muncie Twin	2.5	2
OB4A		Improved Neptune Twin	4	2
OB15A		Neptune Master	16	2
		1932
OB3		Motorgo	4	2	Made for Sears  w/Motorgo label
OB3U		Motorgo Underwater Exaust	4	2	Made for Sears  w/Motorgo label
OB3A		Junior Neptune	4	2
OB3AU		Junior Neptune Underwater Exaust	4	2
OB3B		Muncie Twin	4	2
OB3BU		Muncie Twin Underwater Exaust	4	2
OB4A		Improved Twin	6	2
OB15A		Neptune Master	16	2
		1933
OB4		Motorgo 4	4	2	Made for Sears  w/Waterwitch label
OB3U		Motorgo 4 Underwater Exaust	4	2	Made for Sears  w/Waterwitch label
OB4B		Muncie Twin	4	2
OB4BU		Muncie Twin Underwater Exaust	4	2
OB3A		Junior Neptune	4	2
OB31A		Junior Neptune	4	2
OB4A		Improved Twin	6	2
OB15A		Neptune Master	16	2
		1934
OB5		Motorgo 5	4	2	Made for Sears  w/Waterwitch label
OB5U		Motorgo 5 Underwater Exaust	4	2	Made for Sears  w/Waterwitch label
OB31A		Junior Neptune	4	2
OB61A		Improved Twin	6	2
OB15		Motorgo 16	16	2	Made for Sears  w/Waterwitch label
OB15A		Neptune Master	16	2
OB15B		Muncie Master	16	2
		1935
OB1		Neptune Single	2	1	Made for Sears  w/Waterwitch label
OB32A		Junior Neptune	4	2
OB63		Improved Twin	6	2
OB16A		Neptune Master	16	2
		1936
OB11		Neptune Single	2	1
OB34		Junior Neptune	4	2
OB64		Improved Twin	6	2
OB16A		Neptune Master	16	2
		1937
OB12		Neptune Single	2	1
OB12A		Neptune Single	2	1
OB35		Neptune Single	4	2
OB35A		Neptune Single	4	2
OB65		Improved Twin	6	2
OB65A		Improved Twin	6	2
OB17		Master Twin	16	2
OB17A		Master Twin	16	2
		1938
1A38		Junior Single	1.2	1
1B38		Junior Single	1.2	1
1C38		Junior Single	1.2	1
2A38		Neptune Single	2	1
2B38		Neptune Single	2	1
2C38		Neptune Single	2	1
4A38		Neptune Junior	4	2
4B38		Neptune Junior	4	2
6A38		Improved Twin	6	2
6B38		Improved Twin	6	2
9A38		Neptune 9	9	2
9B38		Neptune 9	9	2
16A38		Master Twin	16	2
16B38		Master Twin	16	2
		1939
1A39		Junior Single	1.2	1
1B39		Junior Single	1.2	1
2A39		Neptune Single	2	1
2B39		Neptune Single	2	1
2C39		Neptune Single	2	1
4A39		Junior Twin	4	2
4B39		Junior Twin	4	2
4C39		Junior Twin	4	2
5A39		Twin	5	2
5B39		Twin	5	2
6A39		Improved Twin	6	2
6B39		Improved Twin	6	2
9A39		Neptune 9	9	2
9B39		Neptune 9	9	2
16A39		Master Twin	16	2
16B39		Master Twin	16	2
		1940
10A1		Junior Single	1.2	1
10B1		Junior Single	1.2	1
10C1		Junior Single	1.2	1
10A2		Neptune Single	2	1
10B2		Neptune Single	2	1
10A4		Junior Twin	4	2
10B4		Junior Twin	4	2
10A6		Improved Twin	6	2
10B6		Improved Twin	6	2
10A10		Neptune 9	9.5	2
10B10		Neptune 9	9.5	2
10A16		Master Twin	16	2
10B16		Master Twin	16	2

Model Number Codes:
There was a loose code of letters and numbers used to identify the early "Muncie Gear" outboard models.
Prefix OB = Outboard
Suffix First Letter (no letter) = Was labeled Private Brand like Motorgo, Sea King, etc.  example: OB3
Suffix First Letter (A) = Was labeled Neptune  example: OB3A
Suffix First Letter (B or C) = Was labeled Muncie  example: OB3B
Suffix Second Letter (U) = Underwater Exaust  example: OB3AU
In the early 40's:  A = Standard Model   AA = Deluxe Model w/ Rewind and Hood
Through the years the numerical number would identify horsepower and year of manufacture.

Neptune   Model Year Guide

1930 - 1940       1941 - 1971      1972 - 1987

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Last Modified: 4/24/04