The time to clean your engine is before you open up any of the engine cover of your Honda CX500, GL500, CX650 or GL650 for a triple or quadruple bypass – there’s almost always grit, dust, dirt, muck and various other things on the outside that you don’t need falling into your motor as soon as you open a cover.
There’s any number of ways of doing this; soda blasting is popular, but if you don’t have the kit to do that a small amount of degreaser – such as kerosene – and a parts cleaning brush or cleaning spray gun (compressor driven) is an easy way of getting most of the muck off. Just make sure you block up any open areas, like the oil filter area here (which ideally should be put back):
Whatever your technique, make sure you do it!