Hello everyone! Long time lurking here for help and opinions, thank you all so far for the knowledge. So couple years back I purchased a 1970 R75/5. I took it all down to pieces, basically restored the whole bike except for engine itself -cylinders, block stayed untouched. My issues lays in engine giving me headache. During my restoration I installed new clutch and replace all seals in there. When I bough the bike oil was leaking from rear main seal. After reassembling the bike I learned it is leaking again! So second questioned my work and went back and replaced it for the second time. Still leaks. Later I decided that a timing chain was never replaced so I went ahead and replaced chain. Along all new seal were installed. Now oil is leaking from camshaft seal, just above points. Great. So I have two leaks. I went through all possible scenarios in my head. here are other issues which I think might be tight to this. Engine oil is getting real black real fast. I measured compression and It was well within specs. I think my engine has a lot of blow by, also because of oil in right tube leading to carburetor. Checked oil pressure valve, seems to be good. So I am thinking it is either rings or valves not sealing properly. Or could this have to do anything with timing of the engine? There is something that I cannot grasp. When I am setting my timing I get both static and advanced where I want it to be, my other side does not correspond. There is a tolerance (cannot remember now) how many degrees is allowed but on my engine I am just past the tolerance, meaning I am off on on side if the other is set precisely. Right side has also lots of carbon on spark plug which could be a result of oil being passed from venting? Or because my timing is off? Sorry I know there is a lot. I am not really an engine builder, I am just a guy with lot of passion and I can use my hands to some degree. This has been bothering me well. I came to a point of needing help!