Thru hulls water pickups for twin mercruiser - fitting locations ?

[mghunter]

Hi

I'm considering putting thru hulls scoop type water pickups on my twin engine 5.0 Mercruiser / Bravo drives.

Reading posts they suggest in front of the engines, noting the sea water pump is on the starboard side of the engine.

Does any one have pictures of their setup to get some ideas.

I found this sample one

[tkeithlu]

Why? Are you having trouble getting cooling water to your engines with the current (neutral?) water inlets? Do you start sucking air at speed?

When you put scoops down there you increase drag and pressurize the water going to your raw water pumps. The disadvantage of increasing drag is obvious. The disadvantage of pressurizing the hoses may only be obvious if you pop a hose at speed and emulate a diving U-boat.

So, I recommend that you arrive at a compelling reason, and there may be one, for changing to scoops before proceeding with design issues.

[mghunter]

Hi

I replaced both transom assemblies (15 years trouble free until I hit something) a few years ago with new 63110002NZ ones and within 18 months had temp issues. Seems the inlet water pipe fell off both drives and also took out my raw water pumps due to lack of water and took a while to work out what the real problem was.

Seems Merc "updated" the water inlet pipe from a simple screw in plastic insert that holds the pipe in the bell housing to a complicated plastic pipe with unbonded flimsy ss clamps that basically requires the drive and more to be removed to refit.

Given I don't want to pay for this design fault each year the pipes disconnect, thru hulls seems to be the easier solution.

[Tetepare]

I’m having trouble understanding where the problem is.

Sounds like new drives that weren’t installed with the proper hardware, and the new design is denigrated because one doesn’t want to do the installation properly.

[mghunter]

I was really just after some pics

Transoms assemblies come from Merc fully assembled including the new design water inlet pipe already fitted (its behind the bell housing)

Just bolt them on and put the drive back on - no need for the installer to play with any of the factory assembled items.

Both pipes coming off at the same time suggests a design issue and is the only thing that is different from my old 2002 transom assemblies (or so I hope).

eg pic of what you get from Merc all fully assembled in a big box

[Tetepare]

I wonder if it was an installation error. Talk to Merc.

Like tkiethlu said, the cons and risks are sufficient to say don’t do it, go back and figure out the failure. Good luck.

[BruceS]

A few inches in front of each engine & after a tap/valve thru a filter with removable lid an inch or so above water line. The "scoop" is really just a filter to stop plastic bags and hunks of seaweed entering and scoop facing backwards. In my area we have a big lobster/cray fishing fleet that are on the hard over winter. Go walk around & look? Just blank off the original intake. On my old boat I put a connection so I could plug in the deckhose/pump in case of pump failure. Saved my once with a plastic bag over the intake. If it's only a ski boat I'd leave it be.

[elittke]

I placed them just in front of the engines, brass pickup scoop, 1 1/2 inch what a difference the water flow is amazing, best thing ever! Used y valves to pick up the transom feed too

[mghunter]

Just a note that after going to a state tribunal, Mercury has agreed to pay for the fix (A$2700) and add some connectivity wires to prevent the clamps corroding.

We'll see how long that lasts.

Suggest if you have the newer transom assemblies you check the water inlet pipe clamps for corrosion (not that that will help but you might avoid being stranded) - they are a bugger to see and replace