Yamato Engine Chronology

1953-present

It can be argued that country of Japan and their support of Kyotei pari-mutuel outboard boat racing literally saved outboard racing in North America:  in the mid 1970's new stock outboard motors were few and far between, with the bulk of the engines in use having been built in the mid-50's, it was difficult to generate new interest in the sport. 

Enter the Yamato Corporation of Japan, and their exportation of the Yamato 80 engine into the United States.  Almost overnight, racers and would be racers could buy a virtually new engine for $400-$500.  The engines were run for one year on the Japanese Kyotei circuit, sent back to the factory and sold refurbished as surplus into the US and other countries.  The result was two new classes of outboard racing for APBA; first the PRO class Formula 350 (which eventually evolved into OSY 400) and the Stock Outboard class 20SS. 

Later imported to the US, the Yamato 102 was introduced into the C Stock class in the mid 1980s.  The current Yamato engine, model 302 arrived in the US about ten years later.  Today, Yamato 80s, 102s, 302s and even the occasional 202 can be found actively racing throughout the US and Canada in some of APBA's most competitive classes.

Listed below are photos of the engines which pre-dated the Y80.  It's fascinating to see the progressive evolution of these engines through the years:

       
Engine Model No. Yamato Y-1 type (28 types)
Production Year: 1953
Manufacturer: International Regatta Promotion of Industry Corporation
CC Displacement: 325 cc
Number of Cylinders: 2
Bore x Stroke: 62.0 x 54.0 mm
HP output/RPM: 15 hp @ 5000 RPM
Weight (kg): 32.0
       
Engine Model No. Yamato 30 Type
Production Year: March 1956
Manufacturer: International Regatta Promotion of Industry Corporation
CC Displacement: 325 cc
Number of Cylinders: 2
Bore x Stroke: 62.0 x 54.0 mm
HP output/RPM: 18.5 hp @ 5500 RPM
Weight (kg): 33.0
       
Engine Model No. Kinuta B-35 Type
Production Year: September 1956
Manufacturer: Kinuta Internal Combustion Engine Factory
CC Displacement: 347.5
Number of Cylinders: 2
Bore x Stroke: 66.0 x 50.8 mm
HP output/RPM: 20.5 hp @ 6200 RPM
Weight (kg): 38.0
       
Engine Model No. Yamato 60 Type
Production Year: May 1961
Manufacturer: Yamato Engine Corporation
CC Displacement: 348.0
Number of Cylinders: 2
Bore x Stroke: 64.0 x 54.0 mm
HP output/RPM: 20.5 hp @ 6000 RPM
Weight (kg): 36.5
       
Engine Model No. Yamato 65 Type
Production Year: April 1965
Manufacturer: Yamato Engine Corporation
CC Displacement: 348.0
Number of Cylinders: 2
Bore x Stroke: 64.0 x 54.0 mm
HP output/RPM: 22 hp @ 6300 RPM
Weight (kg): 37.5
       
Engine Model No. Yamato 65-B Type
Production Year: June 1967
Manufacturer: Yamato Engine Corporation
CC Displacement: 348.0
Number of Cylinders: 2
Bore x Stroke: 64.0 x 54.0 mm
HP output/RPM: 22 hp @ 6300 RPM
Weight (kg): 37.0
       
Engine Model No. Yamato 70 Type
Production Year: December 1970
Manufacturer:  
CC Displacement: 348.0
Number of Cylinders: 2
Bore x Stroke: 61.8 x 58.0 mm
HP output/RPM: 28 hp @ 6400 RPM
Weight (kg): 40.0
       
Engine Model No. Fuji KB-3 Type
Production Year: April 1971
Manufacturer: The Fuji Motorboat Corporation
CC Displacement: 345.0
Number of Cylinders: 2
Bore x Stroke: 60.5 x 60.0 mm
HP output/RPM: 30 hp @ 7200 RPM
Weight (kg): 39.0
       
Engine Model No. Types of World 80
Production Year: January 1974
Manufacturer: World Motorboat Corporation
CC Displacement: 327.8
Number of Cylinders: 2
Bore x Stroke: 60.0 x 58.0 mm
HP output/RPM: 30 hp @ 7000 RPM
Weight (kg): 40.0
       
Engine Model No. Yamato 102 Type
Production Year: May 1980
Manufacturer: Yamato Engine Corporation
CC Displacement: 396.9
Number of Cylinders: 2
Bore x Stroke: 66.0 x 58.0 mm
HP output/RPM: 30 hp @ 6400 RPM
Weight (kg): 40.0
       
Engine Model No. Yamato 202 Type
Production Year: October 1985
Manufacturer: Yamato Engine Corporation
CC Displacement: 396.9
Number of Cylinders: 2
Bore x Stroke: 66.0 x 58.0 mm
HP output/RPM: 32 hp x 6600 RPM
Weight (kg): 42.5

Photos and info on this page used with the kind permission of Monta at www.kyo-tei.com.

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