Well, I gave it a shot with my air nozzle, but it didn't help much -- the dust was really caked on. So I got out the water hose and had it clean in a few squirts. Looks great. The engine is painted and weatherproofed far better than car engines, so I'm not worried about any issues, especially since I am always careful. I let it drip dry, and then idled the engine to warm everything up and finish the job.
very nice process you did there. i also will start it up and run it after washing to heat it up and dry it off. like i said i have washed the tractor/engine off quite a bit and never any trouble (865 hours
b7800- 500 hours rtv 900). i am also very fussy with my equipment. i will use the air compressor first to try to get the dust off, but like you said it gets caked on and usually i will give it a light rinse before all the maintenance schedules (ex: 50 hours) so i have a clean machine to work on. i will also use turtle wax ice on it occasionally (not the engine, but the tractor outside). makes it look brand new. i always turn the pressure washer down way low and my pressure washer is a small electric one 1500 psi. i have heard of gas engines giving trouble, but not diesels. as far as the electronics on an engine, they are sealed for the most part. now i don't go blasting my fuse box area, alternator, or other electric areas with tons of water or high pressure, but i ocassionally do get water on them. heck, my rtv 900, the bed on it will actually drain water right down onto the alternator if parked with the bed down, slightly leaning downhill. i found this out by hauling a hunters bear out of the woods that he shot and the blood ran right down the bed and through a crack between the front wall and bed bottom and caked the alternator. so yes, i put the water to it. that was late last fall, and i have had no trouble starting it since. now i won't go making a habit of hitting the alternator with water, but it hasn't hurt yet.
at my main job at the state transportation dept, we wash off the equipment and engines with high pressure washers and never have any trouble caused by the water. the mechanics just say try to advoid the alternator and fire wall areas. any way, i am not saying that there isn't a problem that the water might cause out there, but just giving you my experiences. heck, dust can cause problems too. 6 one way and half a dozen the other i say.
just thought of one more thing to add. my rtv 900 design, at the rear wheels/ engine/transmission area, the design of it, the rear wheels will splash mud, water all over the lower engine/transmission area. never hurt mine and i haven't heard of any one else complaining that the mud/water splashed up on it has hurt their machine. the engine/transmission is sealed pretty good.
