What should the oil pressure gauge (digital) be reading at idle, mid and 5K plus RPMs? Since I've owned the boat/motor, it's never shown more than halfway on the gauge. Here as of late, I've been seeing blue smoke at start up after long runs and the pressure is at lowest reading on gauge at idle and only registering 1/4 the way up from 4K RPM and up. This is occurring about a 3rd of the time these last couple of months. It's been serviced by Rockwall Marine from day 1 at the recommended intervals. Is this normal, It's hard to tell on these digital gauges as to what the pressure actually is.