I bought a bit of a basket case of a 2001 748S some four years ago, as an idea that it would be a foot in the door for my teenage dream bike. Primarily it had a destroyed motor, but had also been left outside. I've spent the last four years sorting out a motor, and cleaning it up reasonably nice, and am fairly happy with the results. I have a final issue with the bike that I need to resolve before I can really do a break in on the motor and start enjoying it. As a part of the build I fitted an oil pressure gauge to replace the stock pressure switch, I'm reasonably happy that it's functioning as intended. I have been concerned that on starting the bike the pressure climbs to around 6 bar, around 85psi. I believe this is the relief valve pressure, so I think the valve is functioning correctly. I've spoken to the local expert, who built this motor for me. He maintains that the pressure isn't of concern if the oil is in the heads, and if the oil level rises in the sight glass after the motor has been shut off. The oil though is also leaking from somewhere on the heads. I'm not exactly certain of the leak, but I think it's from the rocker arm covers between the camshaft gears, on both heads, but only on that side. I have to guess that the high pressure is at least partially responsible for the leak. I'm running Motul 20W50 mineral oil for the break in, it's about all I can get locally, I'd thought the higher weight might partially be to blame for the oil pressure, but I also think there's got to be some kind of blockage that might be causing this. So my question is are there any reasonable suspects for places I could be looking for blockages that could cause high oil pressure, but also allow that pressure to reach that side rocker cover? Anything else I should consider? Thank you kindly.
