Will raising outboard up one hole help with a boat thats porpoising

S

snake91876

Petty Officer 1st Class
Joined
Jun 25, 2007
Messages
211
14 ft mckee craft with 60hp johnson tilt n trim motor with the anti ventilation plate sitting flush to keel. Boat bounces bad or porpoises after i plane at all trim heights even the lowest setting, when i slow back a little she starts pounding the water. Will raising the motor up one or two holes with anti ventilation plate above the keel help or make this worse.
 
ondarvr

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Re: Will raising outboard up one hole help with a boat thats porpoising

It may help, but you may also need to do other things like move some weight around.
 
JimS123

JimS123

Fleet Admiral
Joined
Jul 27, 2007
Messages
7,993
Re: Will raising outboard up one hole help with a boat thats porpoising

Did it run fine before and this just happened? Or, did you just buy the boat and you're not happy with the performance?

Better look at the hull first. Sounds like you may have a hook in it (warped keel due to improper storage on an improperly adjusted trailer).

If the hull is OK, it may just be over powered. What HP is it rated for?
 
B

Bamaman1

Lieutenant Commander
Joined
May 15, 2011
Messages
1,895
Re: Will raising outboard up one hole help with a boat thats porpoising

If you're porpoising, you need to lower the motor. It really sounds as if your motor and fuel tank(s) are too heavy for a very lightweight boat--tail heavy resulting in the front end sticking up.
 
ondarvr

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Re: Will raising outboard up one hole help with a boat thats porpoising

Bamaman1 said:
If you're porpoising, you need to lower the motor. It really sounds as if your motor and fuel tank(s) are too heavy for a very lightweight boat--tail heavy resulting in the front end sticking up.
Click to expand...

Lowering the motor will increase the bow lift and normally increase porpoising.
 
SleekWolf

SleekWolf

Seaman Apprentice
Joined
Jun 3, 2011
Messages
48
Re: Will raising outboard up one hole help with a boat thats porpoising

JimS123 said:
Better look at the hull first. Sounds like you may have a hook in it (warped keel due to improper storage on an improperly adjusted trailer).

If the hull is OK, it may just be over powered. What HP is it rated for?
Click to expand...

Looking at my boat on the trailer, it appears to have a hook towards the rear where it sits on the rollers. Is this normal? I haven't had it in the water yet since I bought it, so I don't know how it performs.
 
ondarvr

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Re: Will raising outboard up one hole help with a boat thats porpoising

You should post a pic of that area, it will help in getting good answers.
 
JimS123

JimS123

Fleet Admiral
Joined
Jul 27, 2007
Messages
7,993
Re: Will raising outboard up one hole help with a boat thats porpoising

SleekWolf said:
Looking at my boat on the trailer, it appears to have a hook towards the rear where it sits on the rollers. Is this normal? I haven't had it in the water yet since I bought it, so I don't know how it performs.
Click to expand...

Not usually normal, but you didn't say what the materials of construction are, nor the type of boat.

If its not properly supported, or if it is but its innards are all rotten, you might have a problem.
 
You must log in or register to reply here.
Top