I had no real desire or need to pull my engine, but it needed a cleanup after 52 years and several owners. I knew I wanted to renew the original painted finish (Honda Cloud Silver) on the CB350F.... while not pulling it and repainting it in situ. Spousal unit had a steam thing but it wasn't anywhere good enough for this, in fact I hadn't even thought of it... she's got a new more powerful one now, uses it to de-ice the icemaker in the fridge...........
I started with degreasers (naptha or mineral spirits based) and several kinds of brushes. That gets the greasy stuff to the point you can wash it off. More needed, so sprayed with SimpleGreen HD Purple (safe for all metals) mixed 50-50 with water and some dish soap. Many hours of detailing... couldn't get it all. Bought a cheap hand-held battery powered pressure washer that puts out about 50 psi... not near enough for the stubborn stuff, especially deep in the fins, and I finally resorted to a real pressure washer. That got all the stubborn stuff, and I still followed up with all the previous stuff, final rinse with water and isopropanol. A few touch-ups on the casting with a file, wire brushes, all rinsed down with alcohol again. Oh yes, compressed air throughout all this and for final drying.
Got a spare valve cover and had it media blasted, which is a good prep for paint. Painted up like a dream..... masked off all the frame, etc. and lightly sprayed two coats of Duplicolor DE, it looks great. No clearcoat. Plastic buttons on all the original engine bolt heads, to preserve the original finish and patina. I spent a lot of time cleaning up fasteners as I went... all the engine covers are media blasted and will be polished. As discussed elsewhere... likely not going to clearcoat those.
Now that you guys have mentioned it, I could have used a good steam cleaner all along, but alas, spousal unit didn't have the good one yet. Regardless, you'll spend hours and hours........