Help with trim tab

[carloi27]

Hi raiders i need a little help i just got a secondhand 1989 70hp Johnson outboard i notest that the boat lens to the left at full throttle can anyone tell me witch way to turn the trim tab on the motor to mack it ride strait plz ? thanks

[Choicebro]

Hi Carlo,

From what I have found and read about if the motor is pulling to one side then you need to adjust the trim tab on the leg towards the direction it is pulling. ie if it pulls to the right, move tab to the right. This can also create some lean effect.

The trim tab will generally only counter the pulling effect at the trim level that it is set for.

You are asking about leaning, so I guess we need to clarify what you are asking. Leaning can be caused by an off balance in loading of the boat or in some cases boat design.

Are you able to explain a bit further so we can help.

Have you just replaced a motor with this one? if so is the prop rotation the same? What type of boat is it?

Cheers

Kel

[Geoff]

Hi raiders I need a little help. I just got a secondhand 1989 70hp Johnson outboard I notest that the boat leans to the left at full throttle can anyone tell me which way to turn the trim tab on the motor to make it ride straight plz ? thanks

Carlo. The trim tab is like a small rudder & only needs adjusting if , when the motor is straight, the boat is steering to the left or right.

Lean is normally caused by having the motor too low. If the cavitation plate is below the bottom of the transom then the motor needs to be repositioned higher on the transom so the cav plate is level or a few mm higher than the bottom of the transom.

Geoff

Edited August 28, 2012 by Geoff

[dunc333]

+1 to geoff and carlo .to check as geoff said about motor height when running at wot (topspeed)the cav plate should be clearly visible on top of water,you need 2 people in boat to check this ,1 driving 1 observing maybe take a pic and post it at wot and we can verify this cheers dunc 333