Beta 25 fuel starving

[B27]

We can only guess from a distance, you have to eliminate the possibilities one by one.

Remember fuel will only come out of the bleed screw if the tank level is higher than the screw, or the lift pump is pressurising the fuel.
That could be a difference from your old boat.

Some things you can try include:
running from a gravity supply direct to the engine filter
put a pressure gauge on the fuel at the inlet to the injector pump.
clean the tank
Back flush all the lines
Use a big syringe or oil extractor to draw fuel from the tank, and from the tank via the first filter
Put in an electric lift pump

It does not take much fuel to idle an engine at 2000 rpm with no load.
So, are we talking it won't rev in neutral, or it won't rev in gear?
Not reving in gear could be a fouled prop, rope around it maybe?

If the lift pump seems to suck fuel from the tank OK, but you still get starvation, it can be crud blocking the pick up in the tank, which may only show itself when the fuel is flowing continuously.
Running from a gravity tank or outboard tank full of known good, clean fuel should either eliminate the tank, or point the finger that way.

Failure to rev can also be caused by blocked exhaust or air filter, or a fault with the controls.
Or air in the fuel, which can be elusive.

 

[maremostro]

, or it won't rev in gear?

It dies all the same in neutral, sometimes it will give 1200 - 1500 revs , with a swell from the aft will do only neutral.
Loosened the injector one by one just enough to keep it running and the amount t of fuel squirting out is very disappointing

 

[B27]

If you can't work through the various suggestions, then it probably time to get a mechanic to have a look.

There are limits to what can be diagnosed over the internet.
Quite often someone who can actually see the engine will spot a problem in minutes.

I'd avoid messing with the injectors, if it starts and idles and isn't producing lots of smoke, they are probably not your issue.