Thread: Boat fuel tank fill limit valve.

Does anyone have info on the workings of a boat fuel tank fill limit valve?

My dad has a Profile 635H, and in the last couple of days something has changed with this valve (I’m assuming this is the function of this valve but it is different to the ones I can find online in that it seems to have two outlets - one to the tank filler tube, and a return to the tank).

For some reason this valve has started shutting off prematurely and is quite significantly reducing the amount of fuel that can be added to the tank before fuel rises up the filler tube and shuts off the refuelling pump.

Any ideas on a fix - other than removing the valve from the system?