Hot Tanking

[Rabbit on Roids]

yea, the coke you drink... thats the stuff thats way hard on your teeth..

[MJF]

Test dipping in citric acid. Thatīs also in Coke   Dipped block in lye (NaOH) and citric that was so rusty, oily and painted before... Lye removes dirt and paint, citric removes rust. Phosphoric acid leaves protective surface, but citric leaves clean that rusts quicly again.
Test dip with aluminium part and phosphoric acid.

[rallydiesel]

Whether you hot tank it or clean it yourself, make sure to clean out the oil galley. There's a couple plugs you need to remove and replace to do this.

[clbanman]

another option: http://www.stovebolt.com/techtips/rust/rust_molasses.htm

http://www.oldmarineengine.com/discus/messages/1/345.html