1931 Model Year

Designed by Steve Andres

 

NOTE: Muncie – Neptune  models  having a “U” in their  model designation   had  under water exhausts .  Example:  OB2AU


Model Name: 1931 OB15A Muncie Master
Original carburetor Tillotson MS-47A
Magneto Eisemann Model 82D
Cylinders 2
B x S 2 1/2” x 2″
HP 16
Point gap 0.020
Sheer pin 5/32” x 3/4” or 3/16” x 3/4
Oil 2/3 pt. SAE-30 per Gal.
Tank Sheet aluminum
Exhaust Under water
Lower unit Ball bearing
Rope plate 6″ Muncie twin


Model Name: 1931 OB2 Muncie
Original carburetor Tillotson MS-45A
Magneto American Bosch Model FY6-ED2
Cylinders 2
B x S 2″ x 1 1/2
HP 2 1/2
Point gap 0.020
Sheer pin 5/32” x 3/4” or 3/16” x 3/4
Oil 2/3 pt. SAE-30 per Gal.
Tank Cast hammered aluminum
Exhaust Above water
Lower unit Plain bearing
Rope plate 6″ cast aluminum


Model Name: 1931 OB2A Junior Neptune
Original carburetor Tillotson MS-45A
Magneto American Bosch Model FY6-ED2
Cylinders 2
B x S 2″ x 1 1/2
HP 2 1/2
Point gap 0.020
Sheer pin 5/32” x 3/4” or 3/16” x 3/4
Oil 2/3 pt. SAE-30 per Gal.
Tank Cast hammered aluminum
Exhaust Above water
Lower unit Plain bearing
Rope plate 6″ Neptune cast aluminum


Model Name: 1931 OB2C Motorgo
Original carburetor Tillotson MS-45A
Magneto American Bosch Model FY6-ED2
Cylinders 2
B x S 2″ x 1 1/2
HP 2 1/2
Point gap 0.020
Sheer pin 5/32” x 3/4” or 3/16” x 3/4
Oil 2/3 pt. SAE-30 per Gal.
Tank Cast hammered aluminum
Exhaust Above water
Lower unit Plain bearing
Rope plate 6″ cast aluminum


Model Name: 1931 OB2CB Muncie Twin
Original carburetor Tillotson MS-45A
Magneto American Bosch Model FY6-ED2
Cylinders 2
B x S 2″ x 1 1/2
HP 2 1/2
Point gap 0.020
Sheer pin 5/32” x 3/4” or 3/16” x 3/4
Oil 2/3 pt. SAE-30 per Gal.
Tank Cast hammered aluminum
Exhaust Above water
Lower unit Plain bearing
Rope plate 6″ cast aluminum


Model Name: 1931 OB2D
Original carburetor Tillotson MS-45A
Magneto American Bosch Model FY6-ED2
Cylinders 2
B x S 2″ x 1 1/2
HP 2 1/2
Point gap 0.020
Sheer pin 5/32” x 3/4” or 3/16” x 3/4
Oil 2/3 pt. SAE-30 per Gal.
Tank Cast hammered aluminum
Exhaust Above water
Lower unit Plain bearing
Rope plate 6″ cast aluminum


Model Name: 1931 OB4A Improved Twin
Original carburetor Tillotson MS-45A
Magneto Eisemann Model 82D
Cylinders 2
B x S 2″ x 1 1/2
HP 4
Point gap 0.020
Sheer pin 5/32” x 3/4” or 3/16” x 3/4
Oil 2/3 pt. SAE-30 per Gal.
Tank Cast hammered or smooth
Exhaust Under water
Lower unit Plain bearing
Rope plate 6″ Muncie