Engine Identification

Classic Engines


(Source of Information: Field Service Clinic Manual 6166, Form No. 5-1213-1)

In the 1950s, Clinton Corporation developed a system of identification of its engines. The basis of this system of identification begins with the nameplate, which was permanently attached to each Clinton engine at the factory. The reference for all service and repair on Clinton engines will be found on this nameplate. It is very important that the plate remain with the engine. Should it ever become necessary to replace that part of an engine to which the nameplate is attached, make certain to remove the plate and place it on the new part. Listed on this page is additional information regarding the Name Plate as a key to service.

Three basic pieces of information are needed from the engine nameplate to locate the parts needed in the sales-service manual.

Fig. 1

Fig. 1

  1. Model Number
  2. Variation Number
  3. Type Letter

1. How To Find Model (See Figure 1)

The model number (e.g., B-7xx) of your engine is found on the nameplate. Then, by turning to Section 11, Division B-700, you will find the Basic Parts List. For example, if the model number is D-1160, you would turn to Section II, Div. D-1100, etc. In some cases, the model will be shown as D-700-2xxx, which would be the D-7001000 Series or D-700-2000 Series with model variations shown in the last three digits.

2. Variation Numbers

One thing to keep in mind when working with the Clinton manual is that all models are set up in numerical and alphabetical sequence. The model is further identified by the last TWO figures in the model designation number, e.g., B-760, and is sometimes followed by additional letters or numbers. All recent models and future production will have numbers only following the basic model number. The lettering system has been discontinued.

Due to varied employment of many series, there may be a large number of models. A complete list of these models, referred to as model variations, will be found following each Basic Parts List. Under this system of assigning model variation numbers, the first variation from the standard engine will begin with “100.” A typical model number might be 1200-107, for example. The model variation list following each Basic Parts List will tell what parts or assemblies are used on each variation in addition to or in place of the standard parts found in the Basic Parts List.

In the case of the nameplate shown above, by looking in the Model Variation List following the Basic Parts List for the B-700 series, you will find that the B-760-AOB has a special crankshaft, a gear-reduction assembly, and that the gear reducer is mounted in the 12:00 position. If, for instance, a part is needed just for the gear reducer, then you must turn to Section III (Accessories) and look up the part under the appropriate assembly number — in this case, 3800. It is advisable to always check through the variations first to determine if other than standard parts were used.

3. How to determine type:

The type letter is very important, as it designates when a part design change has taken place and the original part setup for thIs model engine will not work. Whenever a part or assembly is not used on all types, this will be noted in the basic model parts list. If no note appears, the part will be found on all types. The type in a Clinton engine is always shown as a suffix letter following the serial number — 120883-B is an example.

The new numbering system that was used in the 1960s (See Figure 2)


Fig. 2

Fig. 2

With the use of the above Mylar nameplate the engine model and serial number are stamped on the cylinder air deflector. These numbers are located next to the Mylar nameplate.

The first digit is used to identify the type engine, e.g., 4-4-cycle and 5-2-cycle.

The second and third digits complete identification of the basic series. Odd numbers will be used for vertical shaft engines, and even numbers will be used for horizontal engines, e.g.,405 will be a 4-cycle vertical shaft series and 406 horizontal.

The fourth digit identifies the starter as follows:

  1. recoil starter
  2. rope starter
  3. impulse starter
  4. crank starter
  5. 12-volt electric starter
  6. 12-volt starter generator
  7. 110 electric starter
  8. 12-volt generator
  9. not assigned to date
  10. short block

The fifth digit was used to identify other information about the engines, bearing usage, metal type, and mounting pattern. Listed below is some additional information:

  1. standard bearing
  2. aluminum or bronze sleeve bearing with flange mounting surface and pilot diameter on engine mounting face for mounting equipment concentric to crankshaft center line.
  3. ball or roller bearing
  4. engine mounting face for mounting equipment concentric to crankshaft center line

The sixth digit indicates that the engine has an auxiliary power take-off and speed reducers.

  1. without
  2. auxiliary
  3. 2:1 speed reducer
  4. no date
  5. 4:1 speed reducer
  6. no date
  7. 6:1 speed reducer
  8. not assigned to date
  9. not assigned to date

The seventh digit indicates when the numbering system was changed. Model-variation numbers assigned after a 7th digit change will not correspond to variation numbers assigned before the change.

The eighth, ninth and tenth digits identify model variations.

You are to use all 10 digits and type letter to properly identify your engine.



In 1961, Clinton Corporation changed its numbering system on engines to make the numbering system compatible with IBM. equipment. To properly identify Clinton engines, it is necessary to understand both the 1950s and 1961 systems.

The Clinton Corporation changed its replacement-part numbering system to make it compatible with IBM equipment. This numbering system consists of three groups of numbers used in identifying the part classification, individual part identification, and if the part is an assembly. To clarify the numbering system, refer to the example below, which is broken down into three groups (See Figure 3).


Fig. 3

Fig. 3

Group No. 1

Part Classification — Each group of like parts have a classification number assigned to it. For example, all heads will have 122 for the first group of numbers.

Group No. 2

Individual part identification within the part classification.

Group No. 3

If the numeral 5 appears In the third group of numbers, the part is an assembly. Absence of a number would indicate the part is not an assembly. In some cases, you will find that a 99 will appear In the third group of numbers. This 99, which is for factory use, denotes that the part is supplied by several vendors.

The three groups of numbers used in this numbering system can consist of three digits for group # 1, four digits for group #2, and two digits for group #3.

During the manufacturing of the Clinton engines in the 1950s through 1961, both numbering systems were used. The service materials that were sent to the distributors carry both old and new part numbers. The new IBM number should be used only when there is no old number listed.

Listed below are sections II-IX, which explain how to use the part list to look up information on the various engines.

Section II

The first few pages of Section II contain the engines that have the new IBM numbers assigned to them. You will notice that some of the basic parts lists cover several model engines. These were set up this way as most of the parts that make up these models are alike. When parts are not interchangeable between the various models, the model they are used on will be listed.

The first page of the basic parts list shows an exploded view of the parts that make up the engine. These parts have individual reference numbers which can be used to find the particular part number assigned; for example, using the 400-0100-000 basic model exploded-view reference number 9, page 2 shows that the part is a part number 5735 breaker point assembly.

All reference numbers listed on the exploded view of the engine are set up in numerical order on the following pages for cross-reference to part number. Once the correct terminology is known on the individual parts, the part numbers can be found without using the reference numbers, as the parts are all arranged in alphabetical sequence. For example, the breaker points would be found under the (B)s.

When working with the basic parts list, you will notice that some parts or assemblies are not completely broken down, such as the recoil starters, electric starters, fuel pump, gear reducers, and carburetors. These parts or assemblies are completely broken down and illustrated in Accessory Section 111. For individual parts that make up these accessories, refer to Section III of the manual.

Following the basic parts list for each model, you will find the model variations, which will tell you what changes have been made to the standard engine. These variations should be checked each time to make certain that the correct parts or assemblies are used on the particular model engine involved. Anytime the variations do not show a parts change for a particular model, the part or parts would be standard, as illustrated or listed in the basic parts list.

Section III

This section is set up to cover the items that are not normally considered a standard part on engines; however, there are a few exceptions, such as carburetors and starters. When working with the manual, you will find that the basic parts list or variations will direct you to Section III for an illustrated parts breakdown on various assemblies.

Section IV

For dimensional information on bases, crankshafts, cam gears, and breaker cams, Section IV should be consulted.

Section V

When information is needed on service-replacement stock number engines, as for exterior dimensions and horsepower, refer to Section V.

Section VI

For information regarding the proper method of servicing and repairing Clinton engines, refer to Section VI and the correct division.

Section VII

When information is needed to find the current stock number of a service-replacement engine needed to replace an older model Clinton, refer to Section VII. This section is set up in numerical order, listing all engines which Clinton has manufactured in past years. Clinton also has set up an interchange with competitive brands to Clinton in this section.

Section VII

For information regarding the Clinton warranty policy, short block, and special service information not listed in Section VI, use Section VIII. Warranty and short blocks will be covered separately.

Section IX

This section is set up to keep service accounts informed on advance service information before it is finalized for proper section of the manual.