My 1991 yamaha sterndrive is going to have an engine overhaul this year, with the guts of the motor replaced.
That said, I ran it on the muffs this morning for 15 minutes to get it nice and warm then looked at the oil pressure. I'm using the Yamaha 2-digit digital tacho, and analog temp and oil pressure gauges.
At idle, somewhere between 600 and 700 RPM, the temp was stable at 140 to 145 F. Happy with that, and barely moved when it was idled at 1500 RPM.
At idle the oil pressure was stable at about 28-30 psi.
At 1500 it was about 20-25psi.
During gentle acceleration the pressure momentarily dropped to about 15-17 then immediately climbed back to above 20.
During decelleration the pressure would rise to about 30-35 then drop back.
As the engine will be overhauled I'm not particularly concerned about the relatively low pressure, but I'm thinking there is a problem with the pump outlet relief valve.
Does that sound feasible?
There does not seem to have been any sign of oil usage and the oil is clean.
Thanks in advance.
That said, I ran it on the muffs this morning for 15 minutes to get it nice and warm then looked at the oil pressure. I'm using the Yamaha 2-digit digital tacho, and analog temp and oil pressure gauges.
At idle, somewhere between 600 and 700 RPM, the temp was stable at 140 to 145 F. Happy with that, and barely moved when it was idled at 1500 RPM.
At idle the oil pressure was stable at about 28-30 psi.
At 1500 it was about 20-25psi.
During gentle acceleration the pressure momentarily dropped to about 15-17 then immediately climbed back to above 20.
During decelleration the pressure would rise to about 30-35 then drop back.
As the engine will be overhauled I'm not particularly concerned about the relatively low pressure, but I'm thinking there is a problem with the pump outlet relief valve.
Does that sound feasible?
There does not seem to have been any sign of oil usage and the oil is clean.
Thanks in advance.