Originally Posted by tjandoverguy
how do you know when the filter dosent filter anymore
does the bowl show debris
The answer is that the filter will always filter, but it will eventually clog to the point that the engine won’t run, then you put in a new filter.
The Vacuum gauge if it’s a good one has a “tattletale” which is another pointer that stays at the highest vacuum achieved, if you run a filter until fuel starvation starts to happen, then you know how much your boat
and engine will pull vacuum wise then you decide just how much restriction you will accept, and change the filter before you get there. Vacuum will be different based on engine load, so at idle you will have a lower vacuum than at high power, that is why you need the tattletale, cause you don’t want to have to go below to look at the thing when the engine is running hard.
I have two filters so I can run longer because if I get into fuel starvation I flip the lever to the other filter.
The red needle is the tattletale.
You can also just change filters at some interval like we do oil
filters, say once a year, that’s easiest and you don’t have to buy a vacuum gauge. However carry spares cause filters are known to clog when you least expect it, and without a spare your options are limited.