If your ignition system is in good shape, here is what I did: Mask and tape the glass around the rear fender area and the rear apron to prevent staining your nice finish. Remove air cleaner and fit a baggie over it and tape in place to prevent spray from getting into carb. Tape the holes in the generator (I used Gorilla tape) – don’t forget that there is also a slot on the bottom. I used 2-1/2 cans of generic “engine cleaner” spray, from the local auto store, spray, wait, then power wash off to a sparkly clean engine that runs cooler and makes you feel better. The hardest part (you can plan on getting dirty) is the underside of the engine, – getting up between the push rod tubes etc. Now that I am rebuilding my engine, I will say that the above got my engine even cleaner than I thought it did.