Hello everyone. I have read this forum for a while now, but this is my first post.
I have a 1976 reinell raider 17 foot bass boat with a 115 johnson w/19P stock propeller. I have completely rebuilt this boat. new wood, foam, electrical, plumbing, floor, stringers,transom, carpet etc. The boat weight is 920 pounds according to the manufacturer. On the first test run I had a top speed of 51 mph, by GPS, at 5400 rpm with 2 people onboard. The water was glass and no wind. I raised the motor up 2" and re-tested. Now I get 49 mph at 5100 rpm with the same water conditions and load. Before raising the motor I could trim all the way up with no prop break, now I get prop break at the very upper end of the trim cycle. I had a buddy drive while I hung off the back to look at the outboard, at WOT the anti-cavitation plate is 1/2 inch above the water line behind the boat. The pump pickup is still covered by water and the prop is not cavitating. Where should the anti-cavitation plate be in relation to the water line at WOT and why did the rpm's go down when the motor was raised? Any input or suggestions would be greatly appreciated.
Thanks in advance, Strega
I have a 1976 reinell raider 17 foot bass boat with a 115 johnson w/19P stock propeller. I have completely rebuilt this boat. new wood, foam, electrical, plumbing, floor, stringers,transom, carpet etc. The boat weight is 920 pounds according to the manufacturer. On the first test run I had a top speed of 51 mph, by GPS, at 5400 rpm with 2 people onboard. The water was glass and no wind. I raised the motor up 2" and re-tested. Now I get 49 mph at 5100 rpm with the same water conditions and load. Before raising the motor I could trim all the way up with no prop break, now I get prop break at the very upper end of the trim cycle. I had a buddy drive while I hung off the back to look at the outboard, at WOT the anti-cavitation plate is 1/2 inch above the water line behind the boat. The pump pickup is still covered by water and the prop is not cavitating. Where should the anti-cavitation plate be in relation to the water line at WOT and why did the rpm's go down when the motor was raised? Any input or suggestions would be greatly appreciated.
Thanks in advance, Strega