by Guest » Wed Feb 21, 2001 12:34 pm
Mark, the problem is that your motor has no vibration isolation built into it's mounting clamps. I used to have a 2.3hp Johnson (same motor as your mariner 2.5) and found that it vibrated the boat. However, because mine was clamped directly to the transom, it was not as bad as what you describe. The rubber washers between your bracket and the transom are most likely too soft to help. I'd try harder rubber (or urethane) washers, or just remove the bracket altogether and clamp the motor to the transom with a wooden and/or rubber pad between the clamp-bracket and the transom.
Kevin, your 4 hp outboard has two rubber rings built into the pivots for the mounting clamp to absorb the engine's vibrations, they are around the drive leg where the motor turns to steer or reverse. Also, your 4hp is a 2-cylinder engine, Mark has a 1-cylinder engine and this too makes a difference. I know this because this past Summer I replaced my 2.3hp Johnson with a 4hp Johnson....what a difference! No more vibration when running the engine!
Rod Johnson (rjohnson24-at-juno.com)