Don't forget that the spark plug tube depth is affected by the thickness of the valve cover gaskests
another reason I call these pacaderm motors Hemiroids
I thought of cutting the tube off at the bottom and letting the spark plug go right to the head. Those Milidon tube seals should work keeping the oil out right? Then silicone the top o-ring to the cover. I know once we put those tube seals on no oil got into the cylinders when spark plug was removed.
Just to play it safe, before I put the spark plugs in, I went to the hardware store and got 8 12mm washers. The 14mm were too sloppy loose on the plugs . I had to open up the 12mm a little bit, but not too much to get them to fit the plug snug.
Using them between the head and tube will give me more than enough height for the gaskets, which may compress enough over time so that I can safely remove the washers. And if any carbon builds up in the bottom threads, a tap will clean that up easily, if need be.
I used the metric washers due to their smaller OD.
