I've wrestled the engine in and out without removing the sump, but it's a PITA.
If you're going to remove the suspension, look into the "frame over engine" method of installation and just do the reverse. Have a friend help you lay it down (on some piled up towels or something soft) and lift the frame off. Take the carbs off first.
I put my engines on a stand and then stuff cut up rags in the intake/exhaust ports, then tape over them. I clean them by hand with a brush, degreaser, etc., and a garden hose, though. No pressure washing.