Gray Motor Company

Detroit Michigan

Two Stroke Marine Engines

To determine the year manufactured

 1. Find Serial number: on makers plate or Stamped on flywheel or cylinder casting.

 2.Disregard last three numbers, fourth number is year manufactured.

To determine the decade of manufacture, the physical properties of engine have to be considered .

1. --1906  First engines on market, these were made by DuBrie Engine Co.( serial no's different than GRAY).

 2. --1907- 08 First  actual engines manufactured by Gray

            models "R" and "S".  one and two cylinders  3-12 HP.

 3. -- 1911-12  Change from gib key to tapered shaft and nut at flywheel.

 4. -- 1912  "U" Model added to line

 5. -- 1914-15 No more oilers. model "S' not in catalog .  water pumps still on front of engine

            driven by the timer shaft.  Model "T" added to the line. Mississippi Sandsucker a 6hp

            model "R" with large aft mounted piston waterpump is in catalog.

 6. -- 1916  By this time the waterpumps are on the rear of the engine, and are a piston pump

           driven by an eccentric on the output shaft. The model "U' has flat bolt down plates as

           inspection covers.

 7. -- 1917-18-19 Not much change  ( WW I ) and starting factory again.

 8. -- 1920 Model "U" Has round threaded inspection  covers.

 9.-- 1927 Two cycle engine production ceases.

These are guidelines and any catalog or other information that can adjust or add to

this list is welcome.

Engine List

Model  Year      Serial No.                      Notes                      Owner

DuBrie

1..-----1906--07 1396 First engines sold by GRAY Ernie Darrow

Gray

"R"

1.---- 1907 16R7673 Early eng, spoked wheel (possible stationary) Al (Rustyal)

2.----- 1911 10R11145  10 Hp single Richard Durgee

3. --- 1911 010R1371 Stationary eng,spoked wheel, 10Hp Bill Schaller

4..----- 1912 06R2922 Detroit Gear box Bill schaller

5..----- 1913 06D3649 Twin Richard Durgee

6.----- 1913. 16R13817 Gray Carburetor Bill Schaller

"S"

1.----- 1910 010s724 Has nut at flywheel, 10 Hp Bill Schaller

2.----- 1911 S11453  Single Miro Forest

3. -----1912 S12296 Single Bill Schaller

4. ---- 1913 04S3349 Detroit oiler and Gear box Bill Schaller

5..---- 1913 06D3642 6 Hp George Coates

"T"

1.----- 1920 124T20863 Twin Bill Schaller

"U"

1. ---- 1912 23012024 Very early, excellent condition Ernie Darrow

2.----- 1914 26U14333 Twin Nick Bettevy

3.----- 1918 3U28714 Single Randy Ryderbush

4.----- 1920 26U10450 Twin J.B.Castagnos

5. ---- 1920 26U10911 Twin Bill Schaller

6.----- 1921 23U11698 Twin Nick Bettevy

7.----- 1922 3U2835 Single Bill Schaller

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