Is less more? 1978 70 hp vs 1995 60 hp

[SeaHorse]

I just bought a newer motor. Here's the specs for these 2 stroke, 3 cylinder Mercs:<br />....................1978 70 Hp......1995 60 hp<br />Displacement........816 cc..........965 cc<br />No of carbs...........2................3<br />Seems like the newer, bigger, more carbs motor should have more power . No?

 

[JB]

Re: Is less more? 1978 70 hp vs 1995 60 hp

Howdy, SH.<br /><br />Three factors to consider here. <br /><br />1. Your '78 70hp is crank rated and the '95 60hp is prop rated. That is worth about 7 to 10hp, making the real, at-the-prop peak hp almost equal. My guess is that the '78 is rated at higher rpm.<br /><br />2. 965cc will make more torque at a given, low rpm than 816cc. The 816cc should need more rpm to develop the same hp. Torque makes boats go, hp ratings make boaters buy engines.<br /><br />3. I would expect better performance from the "60", assuming it is propped correctly.<br /><br />Good luck.

 

[phatmanmike]

Re: Is less more? 1978 70 hp vs 1995 60 hp

hello. i sold my 1976 merc 115hp inline 6. 1600cc, 6 cylinders, 3 carbs.<br /><br />i bought a 1989 merc 90hp. CC's unknown. 3 cylinder, 3 carbs.<br /><br />i could imedeatly tell a difference on my boat which is a 16 foot center console.<br /><br />the 115 screamed and sounded and looked way cooler than my 90hp does on ANY day.<br /><br />BUT.....<br /><br />the 115 gave me 2 miles per gallon at best, usually about 1.75 spinning 5600 rpms<br /><br />the 90hp gives me just over 4 miles per gallon spinning 5800 rpms.<br /><br />the 90hp is more throttle responsive and is EXTREMELY quite. yes they are both 2 strokes.<br />the 90 will put the boat on plane quicker too.<br /><br />have a nice day.<br /><br />mike