Could my boat possibly have no seacocks and strainers?

[JV II]

The mechanic delivering the boat said it does not have seacocks because it receives water from the outdrives.
I looked everywhere in the bilge. I have 3 seacocks. One for the A/C, one for the generator, and one for the salt water washdown, but none for the engines. How can that be? The owner's manual shows seacocks and strainers where there are none. Clearly, the engines are cooled. I burned 240 gallons of fuel on a recent trip. Shouldn't it at least have strainers?

 

[Air O'Nautical]

Nope,
The small pick-up holes in the drives act as the strainer.

 

[Stray Cat]

The owner's manual shows seacocks and strainers where there are none.

You're owners manual likely illistrates both I/O and inboard power options. As mentioned the BIII is you source for the engine's raw water. The raw water circulates through a heat exchanger (if you have closed loop cooling) or it is circulated through the block / heads / manifolds if you have a fresh water cooled engine(s). The water is dispelled through the hub of the prop(s)

V Drives, or straight shaft inboards will require strainers for the engine(s) raw water.

 

[Henry Boyd]

Mike,

The 496/BIII combination historically had poor plumbing for cooling. The raw water pump is located on the front of the engine and does not always do a great job of pulling water through the little holes in the drive and through the various hoses that connect the drive to the pump. The first two years we had out boat we had occasional cooling problems, despite having new impellers each year. Since I also wanted to add a flushout fitting, the end solution was to add a throughhull, valves and tees to supplement the drive pickup holes. Since then there have been no overheating issues. It turned out that what was done was an official Mercruiser modification.

Henry

 

[Bridog]

That seems odd to me. I have seacocks for my 350 Mag Horizons. They are matched to Bravo 3 drives.

 

[Ididntdoit]

Mike,

The 496/BIII combination historically had poor plumbing for cooling. The raw water pump is located on the front of the engine and does not always do a great job of pulling water through the little holes in the drive and through the various hoses that connect the drive to the pump. The first two years we had out boat we had occasional cooling problems, despite having new impellers each year. Since I also wanted to add a flushout fitting, the end solution was to add a throughhull, valves and tees to supplement the drive pickup holes. Since then there have been no overheating issues. It turned out that what was done was an official Mercruiser modification.

Henry

I too just performed this modification using the "official" mercruiser block off kits to neuter the drives (had to cut hose between the bellhousing and drive per the instructions with the kit to ensure flow through cooling of the drive) my engines now only receive water through the seacocks.

 

[JV II]

My last boat had BIII with seacocks and strainers from the factory. This boat never exceeded 160 degrees on the temp guages. I'll have to watch it. So, I assume if an impeller goes bad, the boat has to be pulled since it is probably in the outdrive? The manual as usual is useless.

 

[Jack F]

I believe it’s at the bottom front left of the engine..

 

[Tail Chaser 661]

I too just performed this modification using the "official" mercruiser block off kits to neuter the drives (had to cut hose between the bellhousing and drive per the instructions with the kit to ensure flow through cooling of the drive) my engines now only receive water through the seacocks.

I was google searching all over and looking at Merc parts schematics. Never found a B3 block off kit :smt013
Are your boats rigged with the Scooper type thru hull water pu intakes? I just got a concern of reading a post of... If the engine shut off at speed. Water could get scooped up filling the exhaust leading to water ingestion. Rare, But a possibility maybe. :huh:

 

[fwebster]

Are you reading the Sea Ray owner's manual or the Mercruiser maunal for your engine/drive ?

If this is a real concern to you, you can have a valve and strainers installed in the water line from the drive to the engine. We have a lot of grass in the water in our area in the late summer and almost everyone with your situation opts for this "cool mod".

As far as impellers going bad, don't wait for that to happen. You will need to have your drives pulled and serviced annually anyway. Just have new impellers installed during the service and the labor is almost free since you will be paying most of the labor for an impeller change when the drives are serviced anyway.

 

[Henry Boyd]

I suppose that it could be done by someone who knew what they were doing, was properly prepared with a plug to fit the end of the outdrive hose and prepare to dry vac up water out of the bilge. It wouldn't be my first choice.

Some folks have made comments that they have done impeller/water pump changes while in the water, but that probably is a huge function of the relationship between the waterline and the waterpump. Once the hose end is raised above the waterline the water inflow stops.

As to why your 290 had through hulls and the 330 dosen't, I don't know. You also have the new Seacore BIII and that may be the reason. Possibly the rework to the BIII for Seacore design corrects the plumbing issues?

Henry

 

[1stSeaRay]

With Bravo drives your raw water pump is mounted to the engine, this means there is NO impeller in the outdrive.

 

[1stSeaRay]

I just got a concern of reading a post of... If the engine shut off at speed. Water could get scooped up filling the exhaust leading to water ingestion. Rare, But a possibility maybe. :huh:

The water would have to be forced passed the stationary impeller.....not likely.

 

[Presentation]

....As far as impellers going bad, don't wait for that to happen. You will need to have your drives pulled and serviced annually anyway. Just have new impellers installed during the service and the labor is almost free since you will be paying most of the labor for an impeller change when the drives are serviced anyway.

The impeller is not in the drive on the Bravo III drive.

Thats the Alpha I drive.