My Yanmar diesel owner's manual says to rev the engine before shutting it down. Why? Does anybody actually do this?
why rev. the engine?
- Thread starter Al9586
- Start date
- Status
I could be wrong
But I have been given the same info. "bring the RPMs up" and breifly before shutting down and this will bring the engine heat level down before complete shut down. (increased cooling) Take it for what its worth. It has been claimed its good for the engine.
But I have been given the same info. "bring the RPMs up" and breifly before shutting down and this will bring the engine heat level down before complete shut down. (increased cooling) Take it for what its worth. It has been claimed its good for the engine.
Taking the Yanmar engine course
This Sunday at Phila, I will ask this question. I've seen the same answer but wonder if it is folk lore in handme down information. Jim S/V Java
This Sunday at Phila, I will ask this question. I've seen the same answer but wonder if it is folk lore in handme down information. Jim S/V Java
Shutting Down
As the engine might have been idling for some time I think it is just to give the oil a swish round and to blow any cr*p out of the cylinders. Remember the cylinder walls are only splash lubricated and the oil will drain down from these when the engine is stationary. Also to blow surplus water from the exhaust system as the engine might stop with an exhaust port open thus allowing wet salty air to have access to the cylinder walls. I think I had better start doing it!
As the engine might have been idling for some time I think it is just to give the oil a swish round and to blow any cr*p out of the cylinders. Remember the cylinder walls are only splash lubricated and the oil will drain down from these when the engine is stationary. Also to blow surplus water from the exhaust system as the engine might stop with an exhaust port open thus allowing wet salty air to have access to the cylinder walls. I think I had better start doing it!
Revving the Yanmar
I believe that the manual suggests reving the engine after motoring at low RPM. If you have been motoring at high RPM (i.e., cruising at over 2500 RPM) then the 'reving' is not needed. In fact, there is a recommendation that after running the engine at power, you should let the engine idle for a short period (a couple of minutes?) to allow hot spots in the engine to cool off before shutting her down. Michael
I believe that the manual suggests reving the engine after motoring at low RPM. If you have been motoring at high RPM (i.e., cruising at over 2500 RPM) then the 'reving' is not needed. In fact, there is a recommendation that after running the engine at power, you should let the engine idle for a short period (a couple of minutes?) to allow hot spots in the engine to cool off before shutting her down. Michael
H ow many RPM's
I also read that in the manual and I was wondering how many RPM's would be considered reving the engine. I have always understood reving a gas engine too high without load is dangerous. On a Yanmar 3GM they say max RPM is 34-3600 so what is the maximum RPM you would run it at when not under load. Jim - if you read this please include in your list of questions at the course.
I also read that in the manual and I was wondering how many RPM's would be considered reving the engine. I have always understood reving a gas engine too high without load is dangerous. On a Yanmar 3GM they say max RPM is 34-3600 so what is the maximum RPM you would run it at when not under load. Jim - if you read this please include in your list of questions at the course.
My manual says different
I've often wondered why boaters do that. My manual (Yanmar Manual) says to let the engine (1GM, 2GM, 3GM, 3HM)idle for 5 minutes after pulling in. This will allow it to cool down from the "bursts" that are used when docking. The bursts will drive the temp up, thereby, requiring cool-down.
I've often wondered why boaters do that. My manual (Yanmar Manual) says to let the engine (1GM, 2GM, 3GM, 3HM)idle for 5 minutes after pulling in. This will allow it to cool down from the "bursts" that are used when docking. The bursts will drive the temp up, thereby, requiring cool-down.
My two cents...
My Yanmar manual says the same thing and when I asked a diesel mechanic about it he said that when one revs the engine and then pulls the kill lever-it burns off fuel to prevent sooting.
My Yanmar manual says the same thing and when I asked a diesel mechanic about it he said that when one revs the engine and then pulls the kill lever-it burns off fuel to prevent sooting.
- Status