Try Greased Lighting. Spray it on, let it soak for about 10 mins and take a rag or small sponge and start scrubbing. My coolant hoses and anything rubber that has porous qualities looks as good as new. Takes some elbow grease, but it can be done. BTW-with any high strength solvent, you want to make sure that you dilute per the instructions on the bottle. If sprayed on with full strength, you could actually remove paint.
For the engine cases, the best thing I've used is EAGLE ONE "ETCHING" Mag Cleaner...make sure it says ETCHING on the bottle. Its a mild acid wash...you just spray it on and wait 30 seconds and then hose it off. It works BEST if you use a power washer to spray it off (much better results than just a water hose).
If your talking about the aluminum (engine, swingarm, etc,) then i read on here about using eagle 1 mag cleaner "with etching" and WOW what a difference. Make sure its soaking wet, spray it on, wait 30 seconds (max 1 minute) and spray it off real good. When done you have to WD40 since the bolts will rust. Its one of the first tricks that actually requires no elbow grease what so ever. I was shocked. Good luck
Another product that works good on the bare aluminum is CRL. It is sold at the hardware store and is used to remove lime stains. When I worked at the bike shop we used it to clean the Harleys with bare cases without changing the as cast finish of the aluminum.
I've used spray'n'wash and some steel wool on my pipes and they were, as I thought, beyond being able to have any shine....now they look almost brand new. I think drano has the same acids in it. so that might work also.
I hate to bump an old thread but man that stuff does work WONDERS. Now if I can find something to get the clay off the rubber hoses/electric lines I'll be good to go. Thanks for this thread it's helped me out a lot!
Hey guys thought I would let you know I tried wd40 specialist degreaser on my engine and holy crap I was just trying to clean some grease off but the north Carolina red clay came off too. I did not leave it on very long. but it cleaned it well with no scrubbing. its not shiny or anything just clean looking.