Pushrod Tube Seals

[Luca]

The brownish color on the conrods and rocker arms is oil staining, or a mild "oil blackening," caused by soaking or quenching hot metal in oil.  The more heat/the dirtier the oil the darker it will stain until you have yourself a cast iron frying pan.  Metal porosity will affect the finish too.

Some people, such as metal sculptors, experiment with heating and oil quenching temps/concoctions to produce different finishes.  I've put such a finish on an engine cover bracket that bolts to the carb throat on my 1964 Ariens snow thrower this way.

[montmil]

And in my R65's particular case, some "mechanic" or PO may have flipped the pushrobs end-to-end. Quien sabe?

The last old head gaskets I removed were properly installed as were the new ones going back together. It only takes a quick look to confirm proper orientation. Noting the other posted errors and poor decision making from my bike's POs, I wouldn't be surprised that somewhere in the past thirty-three years a head gasket on one side may have been incorrectly installed. Quien sabe?

There were no metal-to-metal contact marks on my R65 pushrod tube exits as those shown in Mike V's photos -which could possibly explain my witness marks.

Besides the '81 R65's re-seal job, I'm still having fun straightening out multiple minor issues on my kinda recently acquired '78 R100S. The next 'S' job is... pushrod tube seals! Got one weepy and three tight. Going for all four, "Since I'm gonna be in there."

Our Classic Airheads don't always come from Airhead people. Some previous owners never even learned to RTFM.  [smiley=thumbdown.gif]

Let the games continue  [smiley=thumbup.gif]