1976 johnson 115 from old to newer boat.

My first boat was a 76 venture 1650 with a 115hp Johnson. I later found out that the venture was heavier that it was supposed to be and after drilling a test hole confirmed that it was waterlogged. So I started searching and found a 2000 G3 proG185 with no engine. The G3 came with a 150hp engine when it was new but I put my 115 from my old boat, and the boat runs well. The top speed is about 39 mph (gps) at max throttle and trim on smooth water. The engine has always run great since I have owned it, and therefore I never touched anything on it. Lately however I have started having carb issues and need to rebuild them. My question is, (since now I am messing with the engine) is there a way to get more horse power out of this engine? And how? I have worked on cars for about 15 years and have built several high hp engines, but have no clue about what is available for outboards, and what is available for an outboard this old.

Re: 1976 johnson 115 from old to newer boat.

You can, but the cost is not worth it. If you need more power your best bet is to get a bigger engine.

Re: 1976 johnson 115 from old to newer boat.

The easiest/cheapest way is to use bolt-on factory parts. Get some 1 5/16" large throat carbs, some NLA intake filler blocks, a set of high compression heads. Composite reeds are also a good addition. For details check out a 1978/1979 140 engine for possible parts swap. See the factory parts lists at: epc.brp.com. What you will find is that a 115 will holeshot right with a 140 to perhaps 3500 rpm, when the 140 will start to pull away and keep going.