Roll and Yaw Adjusting

[mcat121212]

While cruising at 1/2 to full throtle, my boat leans to port while going straight and turns to the left if I let go of the wheel. Can you please explain the dynamics behind the course correction tab under the cavitation plate so I know which way to move it!

 

[moderator1]

Re: Roll and Yaw Adjusting

Moving to General Outboard Questions. This applies to more than Mercury engines.

 

[Jdeagro]

Re: Roll and Yaw Adjusting

Mcat121212<br /><br />The most common cause of a list to port and steering to port is a result of the engine torque.<br /><br />You may have changed the prop to a Sainless Seal cupped type, or added a hydrofoil which could exagerate the problem.<br /><br />The prop rotates clockwise and at cruising speeds the risitance from the prop rotation attemps to rotate the boat in the opposite direction (left).<br /><br />Give us a bit more information about the boat such as design, length, motor HP and type, fiber glass or aluminium, etc.<br /><br />The list can be easily corrected.

 

[mcat121212]

Re: Roll and Yaw Adjusting

The boat in an 18' bayliner LS. Fiberglass hull<br />& 120 merc. outboard. Thanx for your reply and look forward to hearing.

 

[LubeDude]

Re: Roll and Yaw Adjusting

Is this a new boat to you? Sounds like extreme bow steer.<br /><br />Stick with Nautijohn, he will get you straightened out. I think you have several issues to deal with. Trim and engine hight etc.<br />Eventually Smart Tabs will come up, they will make a new boat out of yours.

 

[Jdeagro]

Re: Roll and Yaw Adjusting

mcat121212;<br /><br />Are you running a Stainless Prop? If so How many blades? Are you running a hydrofoil?

 

[mcat121212]

Re: Roll and Yaw Adjusting

no ss prop and no foil. reg three blade prop

 

[roscoe]

Re: Roll and Yaw Adjusting

Well, to get started, try adjusting your trim tab to the left.

 

[mcat121212]

Re: Roll and Yaw Adjusting

before i read your advise i moved the trim tab to the right. the boat is no longer listing left and the steering wheel straightened out. it is still slighly harder to steer right than left but only very little. Does the angle of the motor(up/down) effect this in any way. i read in another post that motors trim up will cause left yaw and down right yaw. Maybe it was the way i had the motor trimmed last trip????????thanx for your input!

 

[Jdeagro]

Re: Roll and Yaw Adjusting

You want to make sure that the bow is not too far down when crusing, otherwise the boat will "Bow Steer". Too much Keel in the water.<br /><br />Glad you got it corrected.