I have a 21' center console that used to have a 1994 Merc 225-hp carbureted 2-stroke. I keep the boat in a slip (saltwater). A service manager I took the boat to told me that he thought the best way to flush the engine after using it was to tilt the engine up, install a set of muffs with one of those rods that clamp it on tight on the lower unit vents, then lower the engine back down and run the engine for a few minutes in the slip with freshwater going to the muffs from a hose. I also added SaltAway to this ritual. Then, after tilting the engine up a final time, giving the lower unit a good shot with the hose to get as much saltwater off as possible. Not perfect, but probably the best you can do with the boat in the water. The service manager thought it was important to run the engine during flushing -- he thought it would get a lot cleaner than doing a static flush using the flush port near the telltale.
A year ago I repowered with a 2011 Optimax 250. The owner's manual says to flush the engine using the port near the telltale. It says the engine can either be running or not. (However, it seems to me that if you connect a hose to the plug near the telltale, then run the engine with the lower unit in the water, it's going to pick up saltwater from the lower unit -- no?)
I see the Mercury Service Manual, however, talks about flushing the engine either with the flush port near the telltale, or with a set of muffs.
What do you guys think? Given that the boat stays in the water, will I get it the cleanest if I go back to my old ritual of flushing using muffs and the engine running? Or is flushing using the port near the telltale (probably with engine not running) good enough?
A year ago I repowered with a 2011 Optimax 250. The owner's manual says to flush the engine using the port near the telltale. It says the engine can either be running or not. (However, it seems to me that if you connect a hose to the plug near the telltale, then run the engine with the lower unit in the water, it's going to pick up saltwater from the lower unit -- no?)
I see the Mercury Service Manual, however, talks about flushing the engine either with the flush port near the telltale, or with a set of muffs.
What do you guys think? Given that the boat stays in the water, will I get it the cleanest if I go back to my old ritual of flushing using muffs and the engine running? Or is flushing using the port near the telltale (probably with engine not running) good enough?
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