New prop pulling to the right?

[ameyers41]

So, I've only owned a boat for a little over a year, so I'm still a professed newbie. Over memorial day weekend, I bent the heck out of my prop, so I bought another until I can get the old one repaired (and it's always nice to have a spare). Both are aluminum. Motor is a 2003 Yamaha 75 four stroke tiller on a 94 1775 Pro V. I don't believe the prop on the boat when we bought it was the OEM since it was black. However, after a year and no complaints in performance, I replaced it with one with the same specs (13 1/4 x 17). The replacement I bought was a Yamaha OEM. Got it on the motor and took it out and it now pulls HARD right. I've made no other changes in the boat or motor. I tried the trim tab in multiple positions and it still pulls hard right. Any other thoughts on how this can be, or suggestions on how to adjust? The props LOOK identical, except of course the new one isn't bent up.

[minneman]

Its likely that when you damaged your prop you moved the trim tab, or bent it.

the black yamaha props are stainless, you may have some lower unit damage as well.

[cribbageboy]

Being your first prop was an aluminum one, I don't think this is the problem, but if you hit something hard enough, it might have tweaked the shaft just enough to cause problems like what you're describing.

[WARRIOR 2090]

could have bent the skeg that will make them pull

[tweedlap]

Look at your motor from behind. Get 5' behind and kneeling then

take a look for alignment.

tweed

[ameyers41]

I haven't found anything out of the ordinary with the skeg being bent or out of line or noticeable damage to the front of the lower unit. I ran the boat again tonight and I found that if I trim the motor up much higher, the hard pulling goes away. Could it simply be that the new prop, despite the same specs, would not require the motor to be trimmed down as much? I used to run the motor with the trim all the way down and it ran straight. Now, it's up about as high as the fine tuning will go and it runs just fine. Anyone else experience something like this?

Cribbageboy, I did notice that the prop shaft is not perfectly straight. When hand spinning the prop, it's a TINY bit off (maybe 1/16 to 1/32 of an inch). If this was off more than a tolerable amount, wouldn't the symptom be vibration (which there ins't any) more than pulling to one side?

Thanks again for all the advice guys.

[delcecchi]

On my boat, the pull to the side varies considerably with the trim angle while on plane. I was told to trim until steering effort becomes balanced.

[marine_man]

It's entirely possible (and given the difference in color, likely) that your new prop has different characteristics than your old prop did... and trimming it up to alleviate steering torque is considered a typical solution.

marine_man

[cribbageboy]

That is true. I would think you would be getting some vibration if it were a problem.