New to me machine, having a hard time finding out which oil to top her off with. I put 2 gallons of ISO46 a friend gave me in her after replacing a bad hose, but I am thinking that might not be the best for it? I'm still low and need to get more. I have the service manual, but it doesn't state which oil. It says to check the operators manual which I don't have unfortunately. Anyone got a PDF of that btw? Thanks!