Mercruiser mystery leak

[QBhoy]

Guys
bit of a long one, but hoping you can help. Cant remember if I have touched on this before, but here goes
so pretty much since the start of the season, I have had the feeling that my boat has been taking in more water than usual...for a bow rider In Scotland.
To be clear, it always takes on some water, when it rains...just because of the design and covers on it. Mainly from below the windscreen.
Anyway, It seems to have been taking in water perhaps only when the boat has been out and running. Really hard to tell, but at the mooring and when not in use (apart from rain) it is bone dry the next day.
But, when running and up on plane, for around half and hour...I can turn on the bilge pump, from empty half hour previously, then it will pump water for a good 5-10 secs. Then sometimes it won’t. It is so inconsistent. I’m aware of all the usual things like water running from elsewhere on the boat and cleaning etc...I’m also aware of the bellows perhaps being to blame and the position the drive is left in I’ve ruled all that out. Bellows are good, no ingress.
Also to be clear. All water drain lines are good. Core plugs are good. Speedo pipe is good.
Really annoying. Was out tonight for hours and took in no water. But last week, it took in at least 10-15 litres every half hour of running.
Only thing I can think of now is the main water intake from the drive and water pump. I took a picture as best I could earlier. There seems to be a bit of the white plastic male spiggot exposed. Is this normal ? And why is it not double jubilee clipped like the VP ? I’ll try and attach picture and please please, I’m open to other suggestions.
Thanks

 

[QBhoy]

Should the intake hose be further on than this ?

 

[wellcraft-classic210]

1 possibility

I have seen rubber exhaust couplers leak somewhat intermittently.

 

[QBhoy]

1 possibility

I have seen rubber exhaust couplers leak somewhat intermittently.

Hi
you mean from the exhaust headers to the cow horn pipes ?
i have the Corsa marine exhausts. I’ve checked all round the exhaust and engine. Pretty sure it’s not anything on the engine. But seems to be only when engine is running and boat on the move.
Really annoying. Can’t be the bung or bellows. These are out the water when the boat is on plane. God knows.

 

[Alumarine]

Should the intake hose be further on than this ?

Because it's an elbow it can't go farther than it is.

I had a fiberglass boat that took in a lot of water because the rub rail that also covered the seam around the boat between the cap and hull came loose in a spot that got spray when I was on plane.

 

[QBhoy]

Wish it was as simple. Defo not that.

 

[achris]

Should the intake hose be further on than this ?

Nope, that looks fine. I have never seen one of those leak. Double clamping? Not required. That spigot has a lip so once the clamp is done up, the hose just can't come off.

You say Scotland. Not sure if you're in the sea or a Loch. If you're in salt, look or the salt runs. If you're in the fresh, not so easy. Have a look around for loose plugs and taps on the engine block, also have a look at the engine circ pump bearing seal.... The other possibility is the exhaust boots. Being as I only have salt boats to look after, I am always seeing those joints with salt runs on them. Very difficult to get a good seal on them, despite being double clamped.

Chris....

 

[QBhoy]

Nope, that looks fine. I have never seen one of those leak. Double clamping? Not required. That spigot has a lip so once the clamp is done up, the hose just can't come off.

You say Scotland. Not sure if you're in the sea or a Loch. If you're in salt, look or the salt runs. If you're in the fresh, not so easy. Have a look around for loose plugs and taps on the engine block, also have a look at the engine circ pump bearing seal.... The other possibility is the exhaust boots. Being as I only have salt boats to look after, I am always seeing those joints with salt runs on them. Very difficult to get a good seal on them, despite being double clamped.

Chris....

Thanks Chris. Appreciated.
Pretty sure it’s not the engine...and you’re right about the intake hose. Managed to look at a dismantled inner and outer transom unit in the workshop today. Didn’t realise it was angled.
Defo not the exhausts system. Someone mentioned about something to do with steering pin or something...but prettt sure that’s above the water level. To be clear, she doesn’t take water in when not running. Wonder if the oil cooler is to blame.