I have twin 525HPs with closed cooling. Boat is on a lift, so I can't access the drives to flush with muffs. Can I plumb T's with a quick connect (downstream from the seawater pump), and run garden hose freshwater through the heat exchanger/oil cooler/exhaust without cranking the engine? Not worried about flushing the drives. I run in brackish water. I would like to be able to quick connect from the outer hull without opening the hatch or running the engines. Thanks in advance!!

My hustler has what you describe that has one hose bib and a manual switch to change from one sea filter to the other. But, it is under the hatch as part of the center support. It is built into it. Very trick.

they say if you run water thru exhaust without engine running it can go into the engine. if risers are long enough to where water mixes with exh with enough drop you might be ok.

More common you'll find the T's before the pump, you'll have to start the motor to flush. The additional benefit is it will back flush the drives when the motors off. Very common on Volvo

This is what i have on 496ho,s flushes the drives for a few min then fire up and do motors .

Yeah, wasn't sure if that was the case on closed cooled models.

Could we get a picture of your setup. This is something I've been looking to do . I would like to make it a clean looking install. Thanks

Hi crf331 i will take some pictures tomorow its a bit tight in there , shoot me a email and i will get them to you , have to get my son to send them , i have been shown a 100 times how to send pic but still cant do it . mine Ts in to the inlet pipe where it leaves the transom shield on its way to the pump them the pipe goes to a fitting on the transom that your standard usa garden hose fitting srews to from outside the boat . when you are done flushing there are black plastic screw caps on a chain that srew on to the fitting.
All looks very neat from outside . WOW finished

just plumb a shutoff valve into a tee to move direction of water and they make a thru hull hose connection, works great, just make sure you move valve back to drive pick up or you will kill the impellor quick...

What about installing a sea strainer? Mine has a flushing attachment on top. Makes it easy to flush and has other benefits.