Hi, we have VTR 250 turbos on our boat. I notice there is a line with a small cock from just underneath on the inlet casing and it runs to the camshaft space of the engine. It is attached to a pipe fitting drilled onto a camshaft cover. We got 4 turbos and some of them cocks are open and some are closed. I checked and there is a small amount of vacuum on that line.
Looked in our manual, could not find anything. Could anyone tell me what it is for and if it should be opened or closed.