I seem to have read somewhere that if you have pressure coming out of where the dip stick goes that you have ring blow by. When you remove the dip stick while the engine is running you should have no pressure coming from this opening, is this true. How much is too much? I have noticed that when I put the tractor under a load quickly there will be a puff of blue smoke come out. When should one consider doing a over haul, I am new to diesel machines. Also is there matching numbers on Yanmars to check to see if the motor matches the rest of the tractor or that it is a bundled together mixture of parts type of tractor? Sorry for all the questions but I know very little about these tractors and I know on this site there are some very knowledgeable people. And thanks for your help.