Originally Posted by Mr Gazza

I find that a little petrol in a take-away tub and an old 1/2" paintbrush works very well on the engine cases, covers and finned areas.
Put a bit of newspaper down under the engine first, and just work from the top down, mopping up the dirty petrol with a rag as you go.
A solvent de-greaser like Gunk or Jizer (if you can still get them?) is probably a bit more pc these days and you don't need to wipe it off as you go. Just rinse off with water when you have brushed and agitated it all over.

Once a year for a good engine clean down should be all you need

Don't be tempted to use a pressure washer on any part of your bike.. It's just a disaster.

For the areas starting to show signs of paint loss and white corrosion, a squirt and wipe with WD40 or some such will stop it going any further and take away the whiteness that makes it look so bad. Waxoyl is good too... Just a dab where it's needed.