Meh, I'll just buy a new, clean crate engine to replace this dirty one, lol.

 

Go to your nearest motorcycle shop and look for a product called "Bike Brite". DO NOT SPRAY IT ON THE EXTERIOR PAINT. IT WILL STRIP YOUR WAX!!! Spray it on a little liberally, on a cool motor. Of coarse cover your battery & air filter. Let it set about 5 minutes and rinse very well. It will leave a nice finish when it dries on all the black or grey plastic, leaves your chrome shiny, and does a really good job. You can also use it in your fender wells. It is a little expensive but does a really great job.