Can a bracket on a boat be a performance problem?

[mkdool]

Re: Can a bracket on a boat be a performance problem?

J is right, it is a plate between the bracket and transom to spread the load.<br /><br />I noticed the angle of the motor in the photos, is it trimmed all of the way down in them? My motor trimmed all of the way down goes past 90 degrees from vertical. I never run with the motor trimmed up close to the angle of yours in the pic.

 

[johnk86]

Re: Can a bracket on a boat be a performance problem?

Guys, thanks for all the info. To answer a few questions, the picture shows the engine tilted up because I took the lower unit off to see what was wrong. I didn't tilt it all the way back down. Since the, I put on the lower unit and tilted it all the way down and it appears to go slightly beyond 90 degrees. The cavitation plate seems to be about 3.5 inches from the bottom line of the boat. I don't know what the water line is on plane, and without the motor running, its going to be hard to tell. When I speak of the motor reving when the bow goes down, it is when I have the motor slightly trimmed up. That's consistant. So I always run with the motor always trimmed all the way down. Doesn't really rev when the bow comes down then but I still have the porpoising problem. Maybe that's weight? Looks like weight distribution and trim tabs may be the answer. Slick Kam, could you please find out what horsepower your friend has on his boat and whether he's satisfied with it? I was thinking of putting a 200hp on it (the broken engine is a 175hp). Would go for a 175hp, but am scared to put a 150hp on it with fears it may not be enough. Thanks for all your comments!

 

[mkdool]

Re: Can a bracket on a boat be a performance problem?

I'll be back in Va next week and can check on the 86', although I'm pretty sure he has a 140. Also just remembered another friend who has a 2002 20' proline w/a with a 150hp mercury and can check with him also. I have a 200 on my 23' and he leaves me like I'm sitting still. Can't get back soon enough, I'm on the northern tip of Michigan's upper peninsula in a blizzard.

 

[AW]

Re: Can a bracket on a boat be a performance problem?

I won't go over all the good points already made, but the original question was about performance, so I'll add someting I didn't see mentioned.<br /><br />Brackets tend to increase high speed performance at the expense of slow speed performance. As speed increases the lift moves aft, and moving the weight back helps maintain the most efficient attitude. Also having the lower unit farther away from the transom helps stability at very high speed. The cost of this, as you know, is porposing at slower speeds.

 

[walleyehed]

Re: Can a bracket on a boat be a performance problem?

Might be a waste of time to mention this, but with that much set-back, a high-rake bow-lifting prop may be needed.<br />The prop in use may be a stearn lifter????

 

[johnk86]

Re: Can a bracket on a boat be a performance problem?

Thank you everyone for the replies. I've read many, many threads on this board and done a lot of research. I've now ordered a new 200hp HPDI Yamaha outboard to go on the boat. I've also contacted Bennett Marine and will purchase a set of Bennett Trim Tabs based on their recommendations. I have reasoning behind both decisions, but I won't bore you with them him. I will post pictures of the new setup once I get it all up and going. Let me say that this board has been extermely helpful in deciding what to buy. Can't tell you folks how much I appreciate it. And Slick Kam, you can contact me at kusterer at erols dot com if you like. Though I've already decided what I'm putting on the boat, it will be interesting to see what others have done. Also, if you can shoot me a picture of the aluminum plate you put on the transom to distribute the weight it would be appreciated. Don't know that I'll do that now, the transom seems real solid, but it will be good to have for future reference. Thanks everyone!

 

[mkdool]

Re: Can a bracket on a boat be a performance problem?

Be glad to, back in Minnesota for 1 last day, driving back in morning.