cleaning the barrels on my type 3 1600...

hey all...i have recentle removed the tin covers from the engine bay in my type three...and the piston barrel fins are all clogged with old crud and dirt/grease...etc...i cant even see through them....which i was told ur sposed to be able to see the ground through the fins...so...without removing the engine...is there a way to remove alll the gunk? cus that wouldnt exactly help the cooling process...
can i use a high pressure cleaner? and cover important stuf up? or what?

any help would be great, thanks, jonno

yep,when engine is cold is the best,

The only way to do it is with elbow grease, and some $2.00 Shop degreaser let it soak for a while make sure the baffle plate is still on on the underside of the barrells maybe that why u carnt see through the fins.