Soon after publishing our video on How to Pickle an Outboard that’s Gone Overboard, a viewer wondered: is it any different with a four-stroke engine? Wouldn’t a larger, more complex engine present more problems? The short answer to both questions is “yes,” and here’s a more detailed explanation.
With a four-stroke, you’ll also need to drain the engine oil system. The large the engine is, the more complex this is likely to be; there may be oil pumps, filters, and hoses which all need to be completely drained of the old oil and then flushed out with diesel (as well as the crankcase, of course), exactly as you flushed out the powerhead. The key is simply to remove any water and/or potentially tainted oil, blast the system(s) with diesel to displace any remaining moisture, and then refill it with fresh oil. And after the pickling process is complete and the engine is back in service, you should give it another oil change after five to 10 hours of use to make absolutely sure no moisture remained behind.
Here's another look at our our Pickle video, which covers two stroke engines:
On large engines, you’ll also likely encounter accessory parts that need to be addressed: starters and alternators, for example. These should be removed from the engine, submerged in freshwater, and then baked in an oven (on the lowest heat possible) until completely dry. You’ll also want to make 100-percent sure all wiring harnesses and connections get a thorough freshwater bath. In many cases, even when the engine can be salvaged and mechanically it runs just fine, six months to a year after the submersion, those electrical components will start to fail. The safest bet is to simply replace every wire and connection that got dunked, though in some cases, this will prove to be very difficult.
To read the complete step-by-step description on how to pickle an outboard engine that’s been submerged, read our Outboard Overboard: Quick, Pickle It.