R21EC Racor 110A plumbed on both inputs!

[ClearwaterMike]

Got my (new to me) 2013 R21EC with the Yanmar 30HP (197 hours) and decided to change the fuel filters. The one on the motor was practically clogged, but the oddest thing is the Racor in the back by the fuel tank was plumbed with the line from the tank to the "in" port and the line to the engine plumbed from the other "in" port. After I removed the Racor (had to cause the bowl was impossible to unscrew) I saw the pre-filter was practically new, the Racor's bowl was disgustingly filthy, but since no fuel had ever been filtered, its no wonder that the Yanmar filter was blocked up. - YET the engine still ran. Anyone ever look at the plumbing on your racor?

Of course I replumbed the unit correctly, now the system is actually getting prefiltered! this photo is what I first discovered ( both lines are plumbed to the "in"

Here is how I re-plumbed it

 

[Favunclerich]

I'm not sure about your boat, but some R-21's were built without Racor filters. Yours may have been added by a previous owner.