I was wondering these old sa 200's when you change your oil is it normal for the oil to look really dirty? When I got this old sa 200 I changed the oil and added a quart of marvel mystry oil in the crank case to help clean up any varnish or sludge in there and I think it helped some but boy it still seems to be dirty when I change it after just running it maybe 2 hours or so. Is this normal? I do have a picture of the oil if you all would like to see it I can post it? I am still having this strange noise like a knock which concerns me a little and the oil pressure seems like it should be higher but when I get the new oil pressure gauge I'll see if it is different. Ksellon did give me the number of her engine builder that I need to call when i get a chance and see if he can help me a little but right now it's to cold out I'm gonan wait till it gets warmer before I try and drop this pan and see what the bearings look like. Thanks
Chris