Trim Tabs

[Deleted User YDKXO]

Can't answer your problem specifically but, contrary to popular wisdom, it is true that on certain boats a bit of tab down does help speed. My own boat is about 2 knots faster with some tab down compared to no tab at all. Basically the beneficial effect of the tabs lifting the stern are greater than the adverse effect of the drag caused by the tabs

 

[stelican]

Have you had the ignition timing and dwell angle set up. these boats use to achieve 28knots when new although it meant sending people fwd with more than 4 onboard to get on plane. is the antifouling smooth /clean?

 

[ontheplane]

Hi Stelican - that's my problem in a nutshell.

Once on the plane it will get 25kts plus - it's getting it up on the plane that is the problem.

Yes I can send people up front but I don't like keep moving peeps about if I can avoid it underway, and of course the engine's lost a bit of power, and the boats probably got heavier with kit and perhaps a bit of absorbed water over the years.

So essentially its an "over the hump" solution I seek.

 

[ms1]

before fitting tabs might I suggest .... trim the leg back from your current full down position (whicn is driving the nose down) and try adding some ballast in the nose. Having replaced petrols with heavier diesels in my Fairline I settled for 4 x 25 kg bags of sand as far forward as I could get it.