A question for the Merc experts

[NathanY]

My motor is a 1974 65hp Merc 650 3 cylinder with 49.8 cid, a 50 hp of the same year is a 4 cylinder with 43.8 cid. Why make a smaller cid motor with more cylinders? What is the purpose of this?

 

[steelespike]

Re: A question for the Merc experts

Not an expert but Im pretty sure the 4 cylinder<br />50 is a carry over design dating back to at least the 60s and possibly late 50s A much refined and<br /> enlarged version of a 4 cylinder 25 that appeared in the late 40s as a forty cu. in<br />motor.that became a 40 hp in 54 when E/J max were 25hp twins.The 3 cylinders were state of the art when they came out.I believe the 72 merc<br />40 2 cylinder has the same bore and stroke as the<br />companion 72 3 cylinder.65.

 

[tmcalavy]

Re: A question for the Merc experts

Nathan,<br />Merc also made a 65 hp four cylinder, but can't remember if was before or after yours. they are all good motors, 3 and 4 cylinders of any displacement. I've heard some old mechs at John's Old Mercury site badmouth the 3-bangers but don't know why. As long as it runs and is reliable is my motto...don't care if it has 2 jugs or 10. Who knows why engineers do anything?