Sir, I have been using 10w-30 conv. No I do not thread in the dip stick, it would be overfilled. I get a puff of blue smoke after shutting It down for a few days and now I notice a puff after restarting after 30 mins or so. Otherwise runs great I am asking if there is anything I can do to test/verify a valve stem seal leak on a GCV 170 engine? Would a compression test tell me anything?