These engines were named based on the displacement and were produced between 1987 and 1993

Examples:

The names were a three digit number, followed by a letter.

1. The first two digits of the number represented the displacement.
   The 43 in 434A meant the engine was a 4.3L.
2. The third digit was used for version control. A 430 and a 431 are both 4.3L's, however the last digit indicates there is difference between the engines. The numbers at the third digit were not always sequential. 430'5 were built before 431'5, however 432'5 and 434'5 were built at the same time.
3. The letter at the end was also used for version control and was sequential. A 500A was built before a 500B.

Nothing in the name relates in any way to years of production. Some of these engines were in production for less than a year, others for many years.

These engines were built during the joint venture with OMC and were painted a dark charcoal color. They were usually named by long character strings that contain two numbers followed by a series of letters.

Examples:

1. The first two numbers are the displacement
2. Next is a letter that indicates who made the base engine. G=GM, F=Ford
3. After that, one or two letters that note the fuel system and/or output.

   L = limited

   s = superior

   X = exceptional

   i = fuel injected (no I means carbureted)

4. Then one letter for the steering system.

   P = power steering

   M = manual steering

   I = inboard

   X = exact steering

   J = Jet Drive

5. The next two letters are the most important for finding parts. These are random letter pairs that indicate the years of production for the engine.

   MD = 1993-1994

   HU = 1994-1995

   NC = 1995-1996

   LK = 1996-1997

   BY = 1997-1998

   WT = 1998-1999

   EF = 1999-2000

6. The next letter is random and is used for version control

   An "A" may not be the first version.

   A "C" may not have been built before an "S".

   An "S" in one engine's name may not mean the same thing as an "S" in another engine's name, especially if the engines have different displacements or production years.

7. Some names have the letters "CE" at the end. This indicates the engine meets certain emission requirements. The only service part affected is the ECU. These part numbers are noted when needed in the catalogs. These engines went out of production in 2000.

Beginning in 2000 the gas engines are painted red again. The naming system was also changed. The first part of the name is the same as the charcoal engines, up to the letters for the fuel system.

Examples:

1. The two numbers are the displacement.
2. Next is a letter that indicates who made the base engine.

   G = GM

   F = Ford

   OS = Volvo Penta's new Ocean Series sterndrives

3. After that, one or two letters that note the fuel system and/or output.

   L = limited

   s = superior

   X = exceptional

   i = fuel injected (no I means carbureted). (may be lowercase or capital)

4. For 3.0L only, there is an M or P for the steering
5. For Inboard engines only, there is an I after the lower case i. Then a dash ( -) followed by a one or two letter suffix. This is the major change from the charcoal engines.
6. The first letter is the version control, this is present on all current engines.

   -A is the first version

   -B is the second version, etc...

   There is no link between the suffix and production years.

   All engines with -A were not built the same year.

   A 5.7GXi-B and a 5.0GXi-B are not similar.

   A 4.3GL-D is newer than and different from a 4.3GL-C.

7. The second letter, if present is always an F, it notes that the engine is freshwater cooled.

The AQ, BB, and MB red gas engines were built until 1989, and were named based on the horsepower or displacement of the engine.

Examples:

1. The name started with:

   AQ = sterndrive engine

   BB = inboard

   MB = inboard

2. Next came the number for the displacement or horsepower.
3. Most of these also included a one letter suffix, for version control.

An AQ271A is older (and different) than a AQ271B. Nothing in the name relates in any way to years of production. Some of these engines were in production for less than a year, others for many years.