Boat listing and Trim tab question

[Bob M]

This may be a dumb question but I have to ask. Repowered my 2310 with a 4 stoke Yamaha 250. Ever since then the boat tends to list to port when running on plane. I have to adjust the tabs some to compensate even when running the boat by myself sitting on the starboard side. The 2 batteries are in the stern bilge to port. The old 2 stroke oil reservoir was in the starboard bilge. Could the elimination of the 2 stroke oil system be enough to make this difference?

Also think I should put on bigger tabs. This is a Deep V 23 foot boat. What size tabs do you guys recommend?

 

[Bryan 2530]

What prop are you spinning?

The list is caused by the rotation of the prop.

 

[GoodChance]

The 18x9" Bennett tab should be the correct size for you.

 

[DaleH]

I'd also agree you're seeing the effects of the prop torque, but also check that tab/fin on the lower unit of the OB. Bigger tabs, being WIDER than depth of the hull, is best for the best fuel efficiency. If room, I'd go 24" wide by 9" deep off the hull. That's what I use on my 25 and I routinely can dial in a 10% or more improvement in fuel efficiency with tabs deployed.

18" wide by 12" deep (similar surface area as 24x9s) off the hull would KILL fuel efficiency, by causing more drag, if used to set the same running condition as the wider tabs. I've proved this by same 2 boats, same motors, and different tabs installed (wide Bennetts on mine vs. deep Lencos on the other boat).

 

[Bob M]

Thanks for the tab info Dale.

Brian, I am still using the old black steel prop that came with my old 225 ox66 original equipment from Parker. I decided to try it on the new motor and it seemed to get performance matching the performance bulletin.

I think it is a 13 3/4 by 17 but I need to check the boat to see.

Would a stainless prop be any better?

 

[Bob M]

Oops sorry to misspell your name Bryan.

I just realized of course this is a stainless prop but not one of the high end shiny polished models.

GoodChance, thanks for the tab info as well.

 

[Bob M]

I checked and the prop is 13 3/4 x 17 black stainless prop. Is the leaning to port due to a bend in a prop blade or some other characteristic of the prop?