pulling to the right

[neurofish]

I put my newly running (with help from this board) 25hp 1986 Merc on my jonboat and have found that the motor wants to turn to the left causing the boat to go to the right. I adjusted the motor on the transom so that it was centered and then even off center to the right to try and compensate (helped some but did not fix the problem). I adjusted the tilt pin so that it had the best plane, but know that the angle of the prop to the water surface can cause rotation of the motor. It just seems like the pull is more than what this would cause (I have to use quite a bit of arm strength to hold it inline). Any ideas? Is it worthwhile to try and adjust the anode to direct the prop thrust? Any other tricks? I hate to tighten down the steering adjust screw to near locking to to try and fix this.

 

[SeaDawg]

Re: pulling to the right

I'm assuming you have the boat riding level on the water. If not, redistribute your weight before you do what I suggest below.<br /><br />You should have a zinc anode (it looks like a really blunt knife blade) located behind your propeller, mounted to the bottom of the cavitation plate by one or more screws.<br /><br />Loosen the screws and rotate it some to the right. Note how far you moved it. Stick the adjustment wrenches in your boat or tow vehicle.<br /><br />Then go to the water and see if it does better now.<br /><br />If it pulls even harder to the right, loosen it again, and move it the opposite way.<br /><br />When you get done, just make sure everyting is tight. (do not lube the screws either)

 

[ehenry]

Re: pulling to the right

I've got the same engine on the same type boat. I have the trim tab under the cavitation plate adjusted all the way to counter act the torque of the prop and engine. It still wants to pull a little but not nearly as bad. The friction liver now only needs to be tightened slightly to make it comfortable to drive.

 

[wakatoa]

Re: pulling to the right

On my 99 70 hp johnson the trim tab is slightly concave on the right side and the tab is set in the centre. This gives light steering on the plane but you can feel it a bit when you accelerate or are in fast displacement speed. Some tiller steer OB's need heaps of adjustment to the right and will then give light steering on the plane. As the other guys said you have to experiment to find the right spot for it.

 

[neurofish]

Re: pulling to the right

Follow up: I adjusted the trim tab (anode) on the motor all the way to the right and the motor straightened out at WOT. Still pulls a little in mid-range RPMs but not nearly as bad. Thanks.