how to tell a merc 2.0, 2.4, 2.5 apart visually ...

[bigshrimpin]

serial number is also on a freeze plug on the powerhead . . . also check the date on the starter (keep in mind some starters have been replaced). 92 (serial begins with "0D") was the first year of the 2.5L and 91 was the last of the 2.4L. 1988 and later 2.4L should have 1pc heads. Generally speaking the 150's were 2.0L except xr4, xr6, Mariner Magnum II/ III. 2pc top hat style heads (1983 - 1988) 135/150's will have a stamp 3 1/8 and 2.4L will have 3 3/8.

[bigshrimpin]

OC would be around 89 or 90.

[bigshrimpin]

92 and newer carbs will have a stamp on the side WMH carbs.

16's are 200hp carbs :)

wmh - 12 and 13 are 2.0L motors

wmh - 14, 15, 16's are 2.5L motors




Old style wh- carbs . . . the stamp is on the top . . . 1990 and earlier.

wh-20 were the fastest . . . I have 2 sets off 2.4L v225's ;)
wh-22's are the second best 200hp carbs.

Diamond shaped heads are pre-83 motors . . . head bolts on the cylinder walls . . . no oil injection.