I looked at your rebuild pics and it looks like you have the normal notched transom on it after rebuild. The hull was rated for a 125hp back then. What did the 125 weigh back then? Did you do anything to change the floor or scupper height or anything to keep water out with a heavier engine?What does the Merc weigh compared to your existing engine? If it is a hundred lbs, fill sand bags and weigh them to get 100 lbs and set them on the top of the cowl of your existing engine and see how she sits in the water.Having a larger engine doesn't hinder the hole shot of the boat, it's the coming off plane too fast that can ruin your day. Search for a member BlueAgave - he added a flotation bracket and a 150 on it.
Almost done with rebuild, pics coming. 1972 19’6 with new 115hp Pro XS CT 20 inch shaft. 365pounds and added a 28 pound hydraulic jack plate. Raised floor one inch and water level is at 1 1/2 inches below floor. Was hoping for better. So far 14 x 23 mercalloy 4 blade spitfire prop at WOT is 4900rpm at 39mph. Need to drop pitch to 19 and will probably reach top rpm range of 6000/6300rpm and top speed(who cares). Totally happy but I am not a speed demon. Like Rick is suggesting early 70’s 19’6 probably can’t handle over 400 pounds with a 20 inch transom. You would be pushing it maybe with a modern day 150hp four stroke. Actually my jack plate helps block waves that want to flow over transom lol. Maybe a new 115hp would fit your needs? Tough because I almost got caught up in the attitude that everything is a race and needed the biggest hp motor I could fit lol. For me 90% of the time I am on the boat the big motor is off and I am trolling with Minn Kota’s fishing. Cheers T
Hi, I just rebuilt a 1985 196 and after a bunch of pain in the ... with engines I bought a Suzuki 140. The gear box is 2.59:1 which I knew but did not appreciate the effects of when I bought it. I like you am perfectly happy at under 30 MPH which I do with a 3 blade 14*19 proper at 43-4500 rpm and using 4 GPH at 25 mph. I did pick up the transom by 5" when I rebuilt it. the scuppers are under water but it doesn't bother me.
I have a 86 200 and I ran a yamaha 115 fourstroke on it and yes the suppers were below the water. I am currently in the middle of rebuilding it so the transom and the floors have been raised. I love the foustroke and the 115 pushed that hull well but having the scuppers below the water line was a burden to me especially if you fish alone and throw castnets or dump water to clean the deck after catching bait. Based on my expierence i would say if there is a fourtsroke on a classic its safe to assume the scuppers are below the water or the floor and transom has been raised. But thats just my 2 cents