Thanks for all the info. The compressor engine is a IH 4 cyl with a rotory screw (I think). I've ordered a manual for it, but haven't gotten it yet. I started it again and let it warm up for about 15-20 minutes and when I engaged the loader valve (I think that's what it is called, it ran good and then when I turn it back it died, but it didn't puke any oil this time. I started back up and it ran fine after that with no problems. It's a little low on oil so I need to get some oil in it before I run anymore. What oil do you suggest for the screw unit?