Not enough trim tab

[Mberkin]

I have a 1998 4000 express with Cummins 420hp 8.3

I have a 400 pound dingy on the fixed swim grid.

The boat trim tabs have been tested and are working properly but doesn’t have enough to trim to push the bow down to run properly. 

It does improve with full water and when not full of fuel.

Does anyone else have this challenge? Can you add bigger trim tabs? They seem to be custom for the boat.

Thanks in advance

[MC1600]

Fuel, water, and waste tank statuses do have an impact on how I get mine to plane, but then my dinghy is only about 150lbs. I dropped my tabs when installing new zincs this fall and there’s a LOT more action they could take (drop almost to the vertical position). So if you needed more swing, I’d imagine it wouldn’t be more difficult than just installing longer cylinders.

[August Rush]

It is basically one of my few complaints about my 4000 express. I have a 500lb RIB on the back. I went with an all chain rode which added some weight to the bow but still tends to ride bow high. Tabs to me should be used to improve this as it adds a lot of drag. Have been kicking around the idea of Zipwake system. I don't think you can fit larger tabs on the boat since they are shaped to be recessed in the hull.