Hello all,
New member, first question! I recently purchased a used 15' Royal American tri-hull in very good shape that is powered by a 1984 Mercury 70 hp outboard. It runs well (starting, idling, over-all reliable thus far), but does not go above 25 mph with just a driver, and does not seem to hit plane. I tried a couple easy improvements (changed plugs, fresh gas + Sea Foam), and no improvement. Brought it into my local Merc dealer/repair, and dropped~$700 on replacement of rectifier (it had literally melted), stator (used, but apparently good shape), and new CDI box, along with replacement of crispy wiring. Just took it out last night for a very brief run (it was dark and I had inadequate lighting), and I couldn't tell much of a difference. To be fair, it was a very short drive, but should've had time to plane out/hit maximum speed as I was WOT for ~ one minute. Also, I'd had to jump start my boat battery with my car battery. I should also note I have no idea what condition the carbeurator is in, and the triple prop has sizable chunks missing in each prop. Compression testing revealed pressures of 115-125 psi for all three cylinders. Also, from the scant data available about the boat itself (I'd never heard of Royal American; I now know they were built in Warsaw, Indiana for about 4 years), I believe it's weight minus motor is ~ 900 pounds.
I would greatly appreciate and insights/recommendations for improving speed/performance anyone can suggest. I'm heading up to the lake for one final week-end fling tonight and am hoping to get it up to full speed!
Best,
JPD63
New member, first question! I recently purchased a used 15' Royal American tri-hull in very good shape that is powered by a 1984 Mercury 70 hp outboard. It runs well (starting, idling, over-all reliable thus far), but does not go above 25 mph with just a driver, and does not seem to hit plane. I tried a couple easy improvements (changed plugs, fresh gas + Sea Foam), and no improvement. Brought it into my local Merc dealer/repair, and dropped~$700 on replacement of rectifier (it had literally melted), stator (used, but apparently good shape), and new CDI box, along with replacement of crispy wiring. Just took it out last night for a very brief run (it was dark and I had inadequate lighting), and I couldn't tell much of a difference. To be fair, it was a very short drive, but should've had time to plane out/hit maximum speed as I was WOT for ~ one minute. Also, I'd had to jump start my boat battery with my car battery. I should also note I have no idea what condition the carbeurator is in, and the triple prop has sizable chunks missing in each prop. Compression testing revealed pressures of 115-125 psi for all three cylinders. Also, from the scant data available about the boat itself (I'd never heard of Royal American; I now know they were built in Warsaw, Indiana for about 4 years), I believe it's weight minus motor is ~ 900 pounds.
I would greatly appreciate and insights/recommendations for improving speed/performance anyone can suggest. I'm heading up to the lake for one final week-end fling tonight and am hoping to get it up to full speed!
Best,
JPD63