The st-2 seems to pull crank pressure from the rear cover, the older 61r looks as though it uses the back side of the diaphragm as the pressure... also the fuel line running from pump directly to the carb is different... on the 61r the fuel runs directly through holes in the crank case... if anyone has copies of an owners manual for the 61r it would be a godsend... but as far as I can see, all is well. Is it possible a rear cover, or head leak would cause this kind of running? I would be able to check for leaks but cant get it to run long enough to warm up and give me any sign of leaks.

-Andy