'77 Merc 1500 VS '83 Merc

[eggs712]

For a couple of years now I've had a '77 Mercury 1500 on a hull that has a new transom but needs a new floor and stringers, and I just finished getting the 1500 running great.

A couple of days ago, I bought a boat from Craigslist that's in great condition other than needing some new seats; transom and floor are solid on it. It has an '83 Mercury 1150 with even compression and was ran last summer until the prop got busted. Now the guy needs quick money for a surgery, so I got the boat for only $300!

My question is, should I swap motors with hulls? I like the ADI ignition on the 1150, and I think it might be prop-rated and have similar horsepower to the 1500. Both motors have the same thru-hull fittings, so it would be a piece of cake to swap them out. Which motor do y'all guys think is better?


(New boat pics)

 

[Fleetwin]

Re: '77 Merc 1500 VS '83 Merc

The '83' Merc. is indeed Prop Rated. The '77' was crankshaft rated.

Mercury never offered the in line six at ratings over 115 after the new regulations (prop rated) were introduced.

That, alone, should tell you something.

I never thought the Merc. "sixes" were that strong to begin with. I think the '83' 115 was a decent engine.

 

[wired247]

Re: '77 Merc 1500 VS '83 Merc

A little higher compression on the 1500 compared to the late 1150. Other than that they are the same motor internally. Different ignition. Carbs about the same. All things equal the 1500 will be a little quicker off idle and mid range just because of the increased compression but we are talking about 30+ year old motors here . Probably a wash. Try them both. Whichever starts and transitions off idle better use that one.

 

[Chris1956]

Re: '77 Merc 1500 VS '83 Merc

Switch the HP badges and run the '83 until she blows. Then install the 1500, with it's original badges. Of course, Merc experts will be able to tell the difference......

 

[eggs712]

Re: '77 Merc 1500 VS '83 Merc

Thanks for the info guys. Since the power is about equal on both motors and the '83 has better ignition, I'll keep the 1150 on the boat and run her till she dies like Chris said. I'll make sure to start the 1500 every couple of weeks though to keep it in good condition.