Well I don't think a 130 will rip the transom off. I have heard of 115's pushing these boats to about 42 mph. So you might get another couple out of it. Is there any reason not to go with a 90? They weigh less, cost less, and are very reliable. Same basic engine as the 130 I think, just a three cylinder. You could reuse your current prop. Maybe even some of the rigging.
We've thunk on this before.
Hey Polski,Gran drew me out. Your old 85 was a bullet proof engine; with care. We sold lots of them, some on exactly your 17 in the mid 70's. I had the privilege of working for an Aquasport dealer during the mid 70's heyday. I will tell you what I know about them. They were 92 cu inch work horses. The same base design as the 1958 50 hp "450" with lots of improvements. I strongly suggest you run 89 octane at a minimum. Octane ratings changed in 1975 when we were weaned off of unleaded gas and we re- jetted all the V4`s per OMC's recommendation. The oil we have today is far better than anything in those days so no problem there. 50-1 pre mix. Change the gearoil every 40 hours. Your engine had a hydro mechanical shift gearcase, which had a hydraulic pump and screen that needed to stay clean in order to facilitate shifting. She should have come with Champion UL77V surface gap plugs which can be changed for QL77JC4 gap style if you did alot of extended idling to reduce fouling. Since you are heavily oiled by todays standards; every 100 hours or so run some Valve tech carbon cleaner either sprayed into the carbs per the instructions or they have a dump in the tank version to keep the rings from sticking. We did see some of these break rings and trash the powerhead from carbon issues. Compression should be 125-135psi. Keep running this classic outboard. Most outboards die from neglect and lack of maintenance and can go well over 2000 hrs. The days of the two stroke engine are numbered in terms of the next decade or two so enjoy her, then worry about having to bolt on an over weight portly fourstroke that on its best day can't deliver the torque or power to weight ratio that your engine does.
Hey Polski, I strongly suggest you run 89 octane at a minimum. Octane ratings changed in 1975 when we were weaned off of unleaded gas and we re- jetted all the V4`s per OMC's recommendation.