Mercruiser 4.3 stern drive flushing whilst moored in sea

Hi recently purchased a Valliant Vip 2009 with the above Engine (alpha) as it will be permanently moored outside my home in a salt water canal is there a way i can flush the engine in the water ? The high salt content of bahrain waters concerns me a little. Can any one point me in the right direction. Ive seen flushing kits on line but not sure

thanks in advance Dave

With an Alpha Drive it is going to be tough. You will have to build a manifold to divert the water, from the pump in the drive, to go overboard while you are flushing the engine.

.... Alternatively, would it be practical to remove the impeller on the pump in the drive and mount a belt driven pump on the engine ala Bravo?... then just a (bronze) "T" fitting inline with the raw water feed from the drive with two valves ( one 1/4 turn sea cock and a hose "bib".) Attach a short "garden" hose from the "bib" and stick the other end into a 3 or 5 gal pail on board, and let a garden hose free run into the bucket. Just make sure the engine speed is kept down so you don't over run the water available from the hose. With this system you can also a salt remover product in the water. I usual this system with my boat ( it has an engine mounted pump already)... I run about 10 to 15 gal of fresh water ( 5 gal pail) thru engine, then fill pail with correct mix of salt remover product for 5 gal... run engine until pail is almost dry... let it sit per instructions on product label, then run another 5 gal of fresh thru it. You didn't say if your engine has a heat exchanger or is direct raw water cooled. If direct raw water cooled, you may need to run more water thru it to flush than the amounts I noted above. If you elect to build a manifold per Chris's post (not that difficult), you should be very careful with the fresh water flow into the "manifold", i.e., full hose flow at engine idle speed, for example, could cause problems. Were I to do this ( and not install an engine mounted pump) , I'd plumb a 12 VDC washdown pump to take water from a pail fed by a free running hose. Note that most engines have raw water supply rates specified. For example, if I recall correctly, my 5.7 requires 10 GPM per 1000 rpms. You can look up the supply requirement for your engine and size the washdown pump and engine rpms @ flush time to suite.

Your forgetting the impeller also cools the oil in the drive.

No, I didn't. Figured that same water flow , and cooling, thru drive would occur with an engine mounted pump as with a drive mounted one.

Most FWC systems need the 1 -1/4 hose for cooling the gen ii is 3/4 at best coming thru the transom

True... and the OP never responded to my question as to FWC vs raw. In rethinking this, the easiest solution and lowest risk one would be a manifold, i.e., two "T"s (bronze) and 3 valves ( 1/4 turn marine ball) and a washdown pump. A quick survey is that 12 V ones limited to 4 + GPM, while above that needs 120 VAC.
A 4 + gpm one should suffice at idle rpms. A FWC system would "flush" faster, mine only needs about 3 gal total flow ( based on anti freeze in and then out the exhausts in the fall), a raw water system would need much much more. Not sure if the amount is even determinate. The elbows and exhaust manifolds would flush quickly, but the block????.... unless he drained the block first???

The best way is to plumb it with some valves and a thru hull fitting. The impeller in the drive dumps overboard thru the fitting. The engine mounted pumps pull from the thru hull In case of failure ,with a few valves you can bypass the engine mounted pump and use the drive`s impeller to get water to the HX. This would allow reduced throttle setting to get back to dock.