Boat looses power withunder half a tank of fuel... help!

Hi everyone,

I have a 4.55 quintrex escape about a 2005 model. It has a 60hp mercury on the back.

Having trouble when driving with under half a tank of fuel. When its over half runs like a dream. When it goes under half the motor looses power and the bulb goes soft. If its left for 5 mins it can take off again and maybe get 2 mins of drive time before the same thing happens. If someone pumps the bulb we are able to travel at low speeds. The tank has breathers.

The guy who usually fixes the boat isn't sure why this is happening. Has anyone else had a similar problem or any ideas how to fix it?

Pull the dip tubes out of the fuel tank and look for cracks or loose tubes.

As per Chris's suggestion, dip tube most likely culprit.
Also check the fuel level manually - the gauge sender maybe reading off and the tank is actually about empty. Dip tubes don't go all the way to the bottom of the tank (they'd suck all the water and crud) so you could be 'empty' with 3 or 4 galls in the bottom. I've also had fuel lines collapse internally and if the fuel tank is low down, as the suction increases as fuel level drops that could shut the flow.