Sounds like the system is still winterized with RV antifreeze. I'd start by tripping the breaker under the rear seat and seeing if that makes your noise go away before filling the tank.

And one more question. If my boat stays at lake (not driven) for 2 days there is about 0,5 feet water under the engine and the alarm starts to yell. I think the water has to come from the drive to the motorspace?

Proabably a leak from the drive bellows/shifter cables. Be careful, if they rip or tear more, they can turn into a big leak and your boat could end up on the bottom.

Boat is now up and the lak is pretty disturbing. I dorve it yesterday from cottage to harbour for abot 15 minutes and there was pretty much water after that. The boat is on a trailer now and mechanic will come today to check it,

drive bellows and shifter cables are ok. The boat was left a week ago under a thunder storm without top. It wad emptief after that but is it possible that there is water "hiding" somewhere and coming out with time.

The pump noice was the water pump. I took it off under the seat.

Tomorrow we put the boat to lake with mechanic and double check the leak.

The leak comes from steering axel at it is getting worse. Have to take boat up everytime after running so I'm glad I have a trailer for it. So the engine has to come off and change everything from the drive bellows to shifter cables when it's open anyways.

Welcome to boats! My 271 is always needing something.

Well nexr step after repairing this will be new speakers, subwoofer and amhplifier. :-)

Where you planning on putting it? I added 2 6x9's under the rear seat, not sure I could fit a sub there.

On my 271 I removed front cushion and mounted a JL cls110rgw7 with the driver facing front of boat,JL 500/1 powering sub.You wouldn't believe the sound from a single 10" sub encloser is everything.