2016 JSO 419 fuel filter replacements

[Alan]

I am planning on replacing both the primary fuel filter (on engine) and the secondary water decanter and pre-filter (on the fuel supply line) on my 2016 JSO 419. I purchased the boat in July 2021 and I am not aware when they were previously changed so I wanted to replace them both at the start of this season.

Are there any tips that would make the job easier? Also, should the fuel filters be replaced in any order or one at a time running the engine (Yanmar 3JH5E) between each filter change to ensure the fuel is bled through the system each time?

Thank you all in advance for your help and any recommendations.

[Charlie-Bravo]

Hi, different model of boat and a smaller Yanmar here but a similar game, as replacing both filters, air will enter the fuel lines and so might as well be done at the same time, and then bleed all the air out … normally done on the secondary filter attached to the engine via a small screw in the top of the filter housing, and you pump the air out with the little leaver on the lift pump ( assuming yours isn’t an electric pump) the primary filter near the tank will also have a bleed to get most of the air out of it whilst it’s filling, so you might as well attack that end of bleeding things first.
Yanmar kindly auto bleed somewhat, so any tiny bubbles of air get returned to the fuel tank, but get as much air out as you can.

Have a look at the primary filter near the tank, and if it doesn’t have a glass bowl at the bottom for inspection, you might consider replacing it with one that has.
If it is of the CAV Delphi type you could also think about replacement with a top loading filter housing , it’s less messy.

Depending on access, I find replacing Delphi filters is quicker and easier if you remove the filter housing off the boat, change the filter and O rings, then pop it back into position.

Tips of the day …… Pampers disposable nappies to catch fuel ( other brands are available) , a bin bag, and lots of kitchen roll, Rubber gloves are essential as diesel eats your skin!, attempt to catch spilt fuel rather than just mopping it up afterward, it’s quicker and the lingering smell of fuel won’t plague you. sandwich bag clips can be used to clamp shut the ends of flexi fuel pipes if removing the primary filter near the tank.

Off to the boat to do mine today
CB

[Alan]

Hi and thank you for the helpful tips. I have located the "bleeding" procedure in the Yanmar manual.  I assume that by bleeding the the air from the system at the engine that I will in the end bleed the air from the filter/water separator as well. 

I am looking forward to replacing the filters a bit more now, just need to bite the bullet and get the job done before it causes me a problem.

[Alan]

Replaced both filters last week.  The job was much easier than expected and only took a couple of hours including bleeding the air out of the fuel system.  No water in the water catcher however there was a bit of sludge and a few debris (see photos attached).  All now back together and run for 20 minutes to ensure all the air was out of the system.  Thank you once again for the useful comments.

[Charlie-Bravo]

Well done, always good to be familiar with your boats system.

Popped this in mine , hoping it will make future changes easier.
CB