I've seen the thread on different cleaners and I'll throw mine into 
the ring.
I use paint thinner. I have many reasons to use the stuff, like it's 
cheap($1.60/gal),  dries to leave a totally clean, not greasy at all 
surface.  I built a homemade parts washer out of stuff from the junkyard and 
pallet wood.  The basin is about 12"x20"x6", just large enough to put a 
crankcase half into.  So this pump pushes the paint thinner around, through 
a 3.5 gal steel bucket, and back to the wash basin.  Works real good.  I 
washed all my tinwork in it, the case and all the internal parts as well.
  Chris Bridge
  
  Currently building an engine for a ''71 Westy
  E-mail cbridge@vt.edu