Model, Type (Spec.) and Code (Serial or D.O.M) numbers are found on every single engine or O.P.E in the U.S.A. You cannot get parts for any engine or power equipment if you do not specify at least the model number. Below, I will explain what most of theses numbers mean and where they can be found.
| OHH | Overhead Valve Horizontal |
|---|---|
| OHM | Overhead Valve Horizontal Medium Frame |
| OHSK | Overhead Valve Horizontal Snow King |
| OVM | Overhead Valve Vertical Medium Frame |
| OVRM | Overhead Valve Vertical Rotary Mower |
| OVXL | Overhead Valve Vertical Medium Frame Xtra-Life |
| OHV | Overhead Valve Vertical |
| V | VERTICAL CRANKSHAFT |
|---|---|
| LAV | LIGHTWEIGHT ALUMINUM VERTICAL |
| VM | VERTICAL MEDIUM FRAME |
| TVM | TECUMSEH VERTICAL MEDIUM FRAME |
| VH | VERTICAL HEAVY DUTY |
| TVS | TECUMSEH VERTICAL STYLED |
| TNT | TORO 'N TECUMSEH |
| ECV | EXCULSIVE CRAFTSMAN VERTICAL |
| TVXL | TECUMSEH VERTICAL EXTRA LIFE |
| H | HORIZONTAL CRANKSHAFT |
|---|---|
| HS | HORIZONTAL SMALL FRAME |
| HSSK | HORIZONTAL SMALL FRAME SNOW KING |
| HM | HORIZONTAL MEDIUM FRAME |
| HMSK | HORIZONTAL MEDIUM FRAME SNOW KING |
| HHM | HORIZONTAL HEAVY DUTY MEDIUM FRAME |
| HH | HORIZONTAL HEAVY DUTY |
| ECH | EXCLUSIVE CRAFTSMAN HORIZONTAL |
| HSK | HORIZONTAL SNOW KING |
The following two tables contain the last few numbers used in the model number. The first table contains numbers that describe the engine's horsepower. The second table contains numbers that describe the displacement of the piston. Horsepower interpretations are provided but are not part of the model number.
| 25 | 2.5 HP |
|---|---|
| 30 | 3 HP |
| 40 | 4 HP |
| 50 | 5 HP |
| 60 | 6 HP |
| 70 | 7 HP |
| 80 | 8 HP |
| 100 | 10 HP |
| 75 | = 7.5 ci | 3.0 HP |
|---|---|---|
| 90 | = 9.0 ci | 3.5 HP |
| 100-105 | = 10-10.5 ci | 4.0 HP |
| 115-125 | = 11.5-12.5 ci | 5.0 HP |
| 140 | = 14 ci | 6.0 HP |
| 170 | = 17.0 ci | 7.0 HP |
| 195 | = 19.5 ci | 8.0 HP |
| 220 | = 22.0 ci | 10.0 HP |
The numbers will look like this on the engine's blower housing=
Now Briggs and Stratton, on the other hand, uses an entirely different system. Their model numbers describes the entire engine. Everything from the type of carburetor and governor to the starter and charging system.
| 6 | 1,2,3,4 | 0-Horizontal Shaft, Diaphragm Carburtor, Pneumatic Governor. | 0-Plain Bearing/DU, Non-Flange Mount. | 0-No Starter with engine. |
| 8,9,10,11,12,13 | 5,6,7,8 | 1-Horizontal Shaft, Vacu-Jet Carburetor, Pneumatic Governor. | 1-Plain Bearing, Flange Mounting. | 1-Rope Starter. |
| 16,17,18,19 | 9,A,B,C | 2-Horizontal Shaft, Pulsa-Jet Carburetor, Pneumatic or Mechanic Governor. | 2-Sleeve Bearing, Flange Mounting, Splash Lube. | 2-Rewind Starter. |
| 22,23,24,25,26 | D,E,F,G | 3-Horizontal Shaft, Flo-Jet Carburetor, Pneumatic Governor. | 3-Ball Bearing, Flange Mounting, Splash Lube. | 3-Electric Starter--120 Volts, Gear driven. |
| 28,29,30 | H,I,J,K | 4-Horizontal Shaft, Flo-Jet Carburetor, Mechanical Governor. | 4-Ball Bearing, Flange Mounting, Presure Lube on Horizontal Shaft Engines. | 4-Electric Starter/Generator--12 Volt, Belt Driven. |
| 32 | L,M,N,O | 5-Vertical Shaft, Vacu-Jet Carburetor, Pneumatic or Mechanical Governor. | 5-Plain Bearing, Gear Reduction (6 to 1) CW Rotation, Flange mounting. | 5-Electric Starter--12 Volts, Gear Driven |
| 35 | P,Q,R,S | 6-Vertical Shaft. | 6-Plain Bearing, Gear Reduction (6 to 1) CCW Rotation | 6-Alternator Only |
| 40 | T,U,V,W | 7-Vertical Shaft, Flo-Jet Carburetor, Pneumatic or Mechanical Governor. | 7-Plain Bearing, Pressure Lube on Vertical Shaft Engines. | 7-Electric Starter--12 Volts, Gear Driven, Alternator. |
| 42 | X,Y,Z | 8-Vertical Shaft, Flo-Jet Carburetor, Mechanical Governor. | 8-Plain Bearing, Auxiliary Drive--Perpendicular to Crankshaft. | 8-Vertical or Side Pull Starter. |
| 9-Vertical Shaft, Pulsa-Jet Carburetor, Pneumatic or Mechanical Governor. | 9-Plain Bearing, Auxiliary Drive--Parallel to Crankshaft. |
The numbers in the first column represent the engine size, in cubic inches. The second column represents the design series. This number is the first digit after the engine size (displacement). The third column represents the position of the crankshaft, the type of governor and type of carburetor. (Second number after displacement). The fourth column represents the PTO bearing, auxiliary drive and reduction gear. (Third number after displacement.) And the fifth column indentifies the type of starter and charging system. (Fourth number after displacment.)
The numbers will look like this on the engine shroud: