on my forty i had to actually tap the welding rod(1/2 rod) in with a hammer. i tapped the rod in so far that it was almost flush with the block. i needed my vise grips to be able to pull it back out. when i did nothing came out and the system was full. no off the shelf flushes will touch this stuff. so dont waste your money as a matter of fact spend it on beer that way you got something to drink when your rodding it out. as soon as you get the rod in the hole "beer". when you get a dribble "beer" when you get a flow "beer". it will be easier to flush yourself than the block.
it took me hours. and i dont even drink.
