Scoop on 70's 50hp Evinrudes???

[jbjennings]

I'm thinking of buying a used 70's (not sure the year) 50hp evinrude to replace my 3cylinder merc 65hp on my pontoon boat which has a cracked water jacket and water in the bottom cylinder.. I believe the 50hp OMC's are good motors. My dad said the 3 cylinder 65 mercs were weak sisters and the 50hp 'rude would probably keep up. Anyone have any experience with them or any known trouble spots??? I'd like a 70hp OMC but am thinking I may get better fuel mileage out of the 50hp. I'm not pulling any skiers or running races. Just about 3/4 throttle is where I usually run. The guy said it had 180lbs. on all cylinders. I doubt that--they didn't have that much new, did they? He also said he'd run it for me on the muffs. I'm going to look at the lower unit oil, check the compression myself, and look for spark on all cylinders. It's a 2-cylinder, right?
thanks,
JBJennings

 

[jimmbo]

Re: Scoop on 70's 50hp Evinrudes???

The 2 cylinder 50hp. 41.5 cu.in. engine was produce from 1971 thru 75 inclusive. The 71 and 72 models used the hydro-electric gearcase while the 73 thru 75 used the hydro-mechanical gearcase. My only experience with it was in 1973. I thought it was a torquey little engine. I don't think you can compare it to the 3 cylinder merc. The 3 cylinder merc has an identical displacement to the early 3 cylinder OMC loopers.That would make for an interesting comparison.

 

[tashasdaddy]

Re: Scoop on 70's 50hp Evinrudes???

over all i would go with the 78 and newer, and get away from the hydro- mechanical shift. not that they are not good lowers, but if the oil pump goes, the replacement cost of the pump, is what the motor is worth.

the 70hp OMC's are one of the most popular motors with commercial fishermen. the motor is light for the hp, good thrust, and economical, reliable. these motors give more bang for the weight, and buck, than any other outboard.

don't get me wrong, i run a lot of 2 cylinder omcs. got 2 50's and 40 presently, and a 50 merc.

 

[JB]

Re: Scoop on 70's 50hp Evinrudes???

I pretty much agree with daddy.

Avoid the pushbutton gearcase engines.

Either the twin or triple loopers are excellent engines, but I prefer the triples.

 

[jbjennings]

Re: Scoop on 70's 50hp Evinrudes???

Thanks guys,
I decided not to get it. I didn't like the sound of "push button gearcase" either. the guy said it had a lower unit off a motor that had a bad water pump that shifted good and didn't have a drip of water in it and that the old lower unit had a cracked case but the oil pump and gears were good and he would throw it in the deal. However, he said he had never run it on a boat and I didn't like the sound of that. It may have been a good motor but I think I'd like to hold out for a 70hp like you suggested. I've doctored up my merc with a little JB weld on the water jacket--maybe it'll run till I can locate a good 70hp. It's always fun to see the last gasp of an old merc, anyway!
Later,
JBJ