Would a plugged secondary fuel filter make you lose 300 rpm from normal WOT?
I changed the Racor 75900 primary with no rpm change.
With Racor pressure gauges, what RPM should the engine be running when you check the gauge?
With Racor pressure gauges, what RPM should the engine be running when you check the gauge?
WOT should be 2800 but all I get is 2450.
Sunchaser asks all the right questions. If this is a new phenomenon then look to something like a fuel filter. If you are just noticing now, then it could be a bunch of things including being overpropped by a bit. FWIW, I don't hit max rpm either, I am shy by about 200rpm. This was done at the sea trial. Not sure why, I could be over propped slightly.
At the sea trial we hit 2725. So I know that a proper pitched prop would read 2850. But now I am at 2400. A few weeks ago I was 2450. So I am guessing it's the secondary fuel filter since I changed the primary Racors.
Today I did change the secondary and flushed a few larger dirt particles out of the old filter. So next time out I will see if we have gained some ground.
I have a gauge between my Racor 75900 pair. It has a drag needle that has never gotten to the red.
I have a gauge between my Racor 75900 pair. It has a drag needle that has never gotten to the red.
Would a plugged secondary fuel filter make you lose 300 rpm from normal WOT?
I changed the Racor 75900 primary with no rpm change.
I replaced my Racor primary fuel filters and still was 300 rpm from WOT. I then changed out my on engine secondary fuel filter and got back the 300 rpm I had lost. ??
Pgitug,
You missed my point in previous message.
If there is significant debris in the secondary filter, your primary filtration is not up to the task.
it could.
...
When was the last time you cleaned or inspected the hull and running gear?
Ted
Can't see how a fouled hull can affect engine speed. Boat speed yes, but not engine RPM.
A dirty hull is harder to push through the water, obviously. That in turn can create an overpropped condition, whereby the drag is just too great for the motor/prop combo, and RPM's can drop.... Don't ask me how I know... Ha.
My diesel engine doesn't slow when there is an increased load such as headwinds and waves. The engine controls operate a governor, and the governor controls fuel flow while maintaining a constant RPM while boat speed may vary. Gasoline engines don't act like this.