- May 3, 2007
- Reaction score
I have a 16' Sprint Marine boat that started life as one that had an inboard 115HP inboard OMC Turbojet. I purchased the boat after it had been converted to an outboard with a 50HP Johnson. The boat worked fine and did not have a tunnel on it. The boat hull has a semi-V hull design. I wanted to put more power on the boat, so added a 75HP Johnson to it and had a tunnel put on the boat. After this change, the boat has tended to want to ride bow-low when I hit the 3/4 power and higher level. I've tilted the motor back and it helps, but a friend has an almost identical boat and his flat out performs far better and planes perfectly with the motor put into the normal, straight/horizontal position that Outboard Jet recommends. I've studied this and looked at what could be causing the problem to no avail. The tunnel doesn't angle wrong and I actually bent up the 3/4" of metal up beyond the transom, to make sure it wasn't causing the issue. The only thing I see that could possibly be doing this are two areas just off the sides at the beginning of the tunnel towards the bow. These areas looked almost cupped upwards, as if two large boulders were hit (which they weren't). I can maybe see this causing the boat to make the bow force down in the water at 3/4 and above power, but figured I'd check on here to see what you all think. I can strip out the console and floor to pound or use a ram to push the metal down, but decided to check in here and see if anyone has had this issue before. I took the boat over to Karold's welding and he looked at it with me for awhile. He didn't see anything that stuck out as a problem though. If I stick absolutely all of my fuel and weight near the rear, it'll plane out alright at higher powers, but I can't always run like that. And....when I need the power, it'll be in skinny water where the bow riding low is a real problem. I love this little boat, but fighting this planing issue has driven me nuts for a couple years now. Thanks for any tips and ideas.