tuning my rudder

hmmm.     When it drives straight it is straight as can be. It will jump one way,   go a ways and then go the other way. It is not at any specific speed, but it is when I am holding my speed steady. I really won't put much more time into the boat this summer anymore, just wait and dig deeper this fall or winter. Not a big deal, just would prefer it did not do it.

thanks guys !!

Mike

The fishtailing or aft wiggle, may be normal even without any slop in the steering/rudder. The rather flat bottoms of the 60's all did it. My 54 does it even worse!! It is a weird sensation. I feel it is the neutral point of the prop torque and hull going in a almost straight line. There isn't any rudder loading at this point and the hull will flip back and forth.

Had a similar problem with my '64....
Easy way to eliminate one cause is to drop the rudder.A bent shaft will cause some strange things to happen with steerage.
After many tries to solve said situation I pulled the rudder.Even tho I was convinced there was no issues there.
I found the rudder post was bent at the base and had a 5 to 7 degree tilt to aft.Let me repeat this was not visable looking at the rudder from port or starboard, but lying flat you could plainly see the bend at the base .........JMHO.........boat dr

Upon further review....

I took a file out to the dock and hopped in the water. The rudder already is ground down on the starboard side. Let me re-phrase the problem. Fishtailing is not a good explanation. I will be driving down teh lake at 20-25mph and the boat will abruptly pitch right may 8-10*, it will go a while longer, and then pitch the other way. It is not weaving per sé, just turns slightly each time, alternating which way. I did take a couple swipes with the file, so now I just have a shiny rudder egde, and no improvement.

My wifes 68 Mustang fishtails periodically while driving it. I presume that the rudder needs to be ground a bit. Any suggestions? Which side should I do ? I have an angle grinder.
As I recall, I should just take a couple swipes at it, and test drive.

289 RH rotation.

Any advice is welcome.