Porpoising Assistance

[tbharris]

I have an older aluminum 13' light weight rowboat with a new to me 2006 merc 4 stroke 9.9 that porpoises with just one person. After adjusting trim on the motor (it has three positions) I cannot get it right. The motor is heavier than the old 10hp evinrude. Old motor is 67 lbs, new one is 84 lbs. Adding weight in the bow fixes the issue, however, I was wondering if anyone has experience with a hydrofoil on a small outboard. I hate to add this, but it may be better than non needed weight up front.

Thanks in advance.

 

[racerone]

Time to test with a simple wedge between motor and transom.

 

[tbharris]

to change the trim?

 

[JimS123]

I have tons of experience with hydrofoils on small outboards. In your case, that isn't what you need.

I doubt that the extra 17 # is the culprit, per se'. You need to trim the motor in more.

 

[tbharris]

Jim123 - thank you. That is exactly the assistance needed.

 

[airshot]

Why not weight moved forward to balance your boat?? Adding a hydrofin will increase drag and cause your motor to work harder. It may fix your issue but not a solution to your problem. Fins are fine if nothing else fixes the problem, but if the problem can be fixed without the fin your better off. Get a milk crate and things like extinguisher, anchor and line, tool kit, flares and other necessary items can be placed where ever needed for balance.

 

[jimmbo]

Rebalancing the Load or adding a bit of Ballast , is preferable to trimming the engine In excessively