Spray it down with simple green or some other bio-friendly degreaser and let er rip with the power washer. Hold the nozzle away and don't force the jet directly at areas like the air intake, spark plug boots, or distributor/coil packs. You don't want to get water inside a component that may rust because it won't dry out well. After cleaning, I'll run the motor for about 30 minutes to warm up and evaporate the water even faster.

Silver,

If she is on the trailer...why not just a can of "gunk" and a garden hose? It has always worked for me....

She is on a trailer. I have some Gunk. Any problems between it and the fiberglass, bilge pump and transducer in the bilge?

Hopefully I will get around to it after I repack the bearings and take care of a few other things.

Try to keep and high pressure spray off the back of the engine. I used a high pressure sprayer at the end of season one year and early the next season my gimbal bearing developed a really nice growl. It failed due to water intrusion and there were no leaks in the bellows or shift cable. The best we could figure was that water got into it from cleaning with the high pressure sprayer. I now just put the bilge plug in and partially fill the bilge with water and dish soap then use a rag/brush/hand to clean everything else.

That's exactly the caution I was going to offer, in that the bellhousing is not totally closed so any water that gets behind the engine can get to the driveshaft splines and gimble. Plus, there are a lot of electrical connectors you do not want water in. Using a pressure washer to clean a marine engine is really overkill. I'd use an engine cleaner and maybe a pump sprayer like you use for lawn chemicals, I have one that I leave on the boat to clean up the mooring cover after a visit from the birds. Some spray on engine cleaner, cleaning brushes and a light spray of water in the right places should work.

Like the others have said, I would be concerned about cutting things up, based on the amount of pressure (3000 psi).

I used an electric pressure washer to clean the engine and bilge of my boat, it was only 1750 psi. I managed to disintegrate the vent ducts pretty good, so watch out for that kind of stuff.

With a gas powered unit, I would be worried about cutting into wires and hoses.