Re: 1970 115 power head swap?
I was under the impression that all early V4's were 4 spline up until around 1974 or 1975? I stripped a blown 1974 that had that same looking spline.
From what I read, the 85hp is sort of all by itself in size and design? (lower displacement).
As far as the 115 power head, it came from a low hours but fire damaged motor. The motor that it came from was in A1 shape other than a burnt cover. It was an electric shift motor. I didn't care to mess with the electric shift and the solenoids were not working, so I parted it out and saved the power head.
I did get it to fire and run briefly when I took it apart. I fogged the cylinders and put it on a shelf for future use hoping that one day I'd find a use for it, even if it were only the block or as parts. From what I can see, that era of V4 is all by itself? I was originally just looking for a motor for a boat I have here that needs something in the 100 to 140 range. I'd swap it for anything I can use. I have a 1976 mi and lower here thats in good working order too. The power head on that is tired, I believe its problems came from too much oil, it's badly carboned up and needs an overhaul. That motor also needs a tilt and trim unit, or at least a good set of rams, new lines, and an upper bracket.
My problem with the 85HP is that for the added weight over a 3 cylinder, I don't gain much. I'd almost be better off just running a 70 or 75 HP? It would be easier on fuel, and the transom. That and it's still a pretty small motor for a boat that's rated for up to a 150HP. (I do have a good running 175HP, but I hate to overpower a boat like that, even though its not any heavier than a 150hp. If I could tune down the 175, I'd already have a good motor for that boat.
Also, can an electric lower unit be converted? (Same housing?)