Histroy of the Mercruiser Alpha Sterndrive

Beginning in 1983 Mercruiser introduced the R/MR/Alpha 1 series of sterndrive models. These units differed greatly from previous years not only in design but also in that the flywheel housing on the engine changed at this point. This creates one of the big break points customers should be familiar with when inquiring about re-powering older boats. Since the flywheel housing changed from 1982 to 1983, you cannot couple a new engine to a pre-1983 sterndrive unit as the rear engine mount spacing differs on the new engine and therefore will not match to the old style inner transom plate. The other difficulty is that the newer 14 inch flywheel utilize a larger coupler that prevents re-using the old flywheel housing on the new engine.

R/MR/Alpha Generation 1 model began in 1983 and ran production through 1990. The Serial Number Range for these models ranged from 6225577 Thru 0D469858

Alpha Generation 2 model was introduced in 1991 and are currently still in production. The Alpha Generation 2 models have been broken into several different Serial Number Ranges as follows:

1991 thru 1995 – 0D469859 Thru 0F679999

1996 thru 1997 – 0F680000 Thru 0K999999

1998 and Up – 0L100040 And Up

Mercruiser alpha 1 water pump kit
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