boat pulls hard right on plane. steering all over at slow speeds

[heckhole]

I have a mid 70s Evinrude on a fiberglass King Fisher.

I don't know the proper names for the parts but the cavitation plate has large wing like composite plates mounted to it.

At slow speeds, the boat goes left and right on its own, it's nearly impossible to go straight. Makes for power loading to be extremely difficult, or just trying to cruise around.

If I let go of the wheel at any time to boat turns HARD right. The wheel or motor isn't moving either.

I've noticed under the cavitation plate, there is a circular thing built into the lower unit, it has a fin pointing down. At one point it appears to have been tacked in a fixed position, so that the downward pointing fin was parallel with the shaft. It's broken free (must be recently because I don't recall these issues from last year). It only spins about 1/4 clockwise before the broken tack welds stop it.

I can post pictures if needed.

 

[jbcurt00]

That is the problem, thats the trim tab to help counter prop torque and is supposed to be fixed in place via a screw, not welded.

I wouldnt use the boat until you get it corrected.

Screw probably got stripped or lost. Idiot fix to weld it, IMO.

 

[bruceb58]

That piece that spins around is a trim tab and it needs to be fixed to prevent your engine from turning hard right when you have power. Ig the motor wants to turn right, the front edge of the trim tab needs to be pointing towards the left.

Some wandering at idle speeds is completely normal. If what you are feeling is more than that, it is possible there is slack in your steering. Have someone hold the steering wheel so it doesn't move and see if you can turn the motor back and forth.

 

[heckhole]

There is a minimal amount of slack in the steering. Maybe a 1/4 inch of movement.

The side to side movement at slow speeds is EXTREME. the only way to minimize it is to trim the motor up high.

The cavitation plate obviously took a big hit at one point in its life. It has been welded, but it is square. There is no place for a set screw on the trim tab. I'm guessing that was damaged and that's why it was tack welded in place. I have no option but to tack it back into position. Should I tack it parallel to begin with?

 

[Fed]

There should be a bolt right in the middle of it, look underneath.

 

[heckhole]

Will have a look tomorrow. I didn't look too hard, I saw it was tacked, saw that it could rotate and figured that ain't right.