Motor wedges

poolecw

Petty Officer 3rd Class
Joined
Feb 27, 2005
Messages
86
I have a 16' Carolina skiff with a 50hp E-tec. I have problems with the boat tending to porpose. I am not interested in smart tabs or hydrofins. My dealer suggested motor wedges. Does anyone have experiences with wedges? Will they eliminate the porposing?<br /><br />thanks,<br />Chris
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,973
Re: Motor wedges

Well,....... I haven't messed with Outboards in Years......<br />But,...<br />I'd think that you've got to Figure Out WHY it's porposing,..... Before you can come up with the Cure.........<br /><br />Wedges will cure a problem of the motor being Too Trimed Under, Or Not Down Enough......<br /><br />What Happens when you Change the Trim Angle of the motor NOW ?????<br /><br />Is the last 4' or 5' of the Hull Running Surface STRAIGHT ???<br /><br />Is the motor mounted Too High ?? Too Low ??
 

Jdeagro

iboats.com Partner
Joined
Jul 30, 2003
Messages
1,682
Re: Motor wedges

Poolecw;<br /><br />I won't try to sell you Smart Tabs simply because your dealer has already directed you away from this to wedges. <br /><br />First you need to understand why the boat is porpoising, and what the wedge will do. The boat is porpoising because the balance is too far to the stern. A common problem with most outboard and stern drive boats. The bow is easily pushed up by the water because the weight is toward the rear of the boat. What goes up must come down. = Porpoising. <br /><br />The wedge usually is used to change the transom angle so that the motor can be pushed further under the boat inorder to lift the stern. Lifting the stern pushes the bow down. This facilitates getting on plane, and can increase the bow pressure to help eliminate the porpoising.<br /><br />However this is at the expense of the prop efficiency and overall performance. In other words the propeller will be constantly running at angle and loose forward thrust. Fuel economy will also be reduced. You will be asking the prop to do two jobs, correct the boat handling and propell the boat. It's a compropmise.<br /><br />Here are some suggestions, as stated above, check the motor height, Check the bottom of the boat for hooks or dammage. You may wish to change the balance of the boat by shifting weight, but no matter what you do when you make permanent changes to the balance, it will compromise something else. <br /> I personally think wedges are not good.<br /><br />Good Luck!<br /><br />Call me if you wish more information 800-233-0194.
 

poolecw

Petty Officer 3rd Class
Joined
Feb 27, 2005
Messages
86
Re: Motor wedges

Thanks for you comments. I think the Smart Tabs are great, but I don't won't them on this particular boat. The cavitation plate sits about 1/4" above the bottom of the hull. If I lower the motor, the porpose will be reduces, but it will negatively effect performance. The boat is a Semi V 16' Carolina Skiff. When on plane, the back 4 feet of the hull is in contact with the water. This part of the hull is flat, but the last 10 inches or so appear to make a slight curve downard. I guess they designed it into the boat to try to keep the bow down.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,973
Re: Motor wedges

This part of the hull is flat, but the last 10 inches or so appear to make a slight curve downard.
That's the Problem...........<br /><br />It's called a Hook...... Fill It In........<br />Straighten the last 4' of the hull............
 

Jdeagro

iboats.com Partner
Joined
Jul 30, 2003
Messages
1,682
Re: Motor wedges

Poole;<br /><br />Do you have a hydrofoil on the motor. If you have a hook in the hull and a hydrofoil you may be pushing to bow down too hard. Actually either of these could do that. This would cause porpoising as well. The bow get pushed in then the water squeezes it out, and then the cycle repeats.
 
Top