I haven't actually re-checked my engine manual but IIRC the stock engine filter (primary? ) for a Yanmar 3HM35F is 2 micron. The boat came with a Racor 200FG installed between the tank and the engine which I believe makes this the (secondary?). Recent discussions on this list have led me to reconsider running a 2 micron in the Racor but aside from needing to occasionally vent air from the Racor I have had no other adverse effects and haven't changed either of the filters in about 4 years.
After closing on the boat I chased what I thought was an air leak in the fuel system for months. I got pretty good at venting the system and learned what worked and what didn't. What was needed and what wasn't. The mechanic advised me to avoid operating the vent screw on the filter housing since he had seen his share of stripped vent screws. Heeding his advice, I resorted to primarily venting from the vent port on the outlet of the Racor and the vent screw built into the banjo fitting on the high pressure fuel pump. I soon learned that the vent screw on the HP pump was prone to stripping too! Ugh! In my time of need I simply JB Welded the screw in place. Now I was forced to vent from nothing but the outlet of the racor. I noticed quite quickly that the vent port was poorly located and provided ineffective removal of the air since it wasn't close enough to the high point. The only other places to vent wer actually loosening banjo fittings along the fuel circuit but unfortunately they use copper gaskets which are really designed to be a one time use item otherwise they leak. Another problem that I encountered was that bleeding the engine required a considerable amount of fuel - upwards of a gallon to flush out all the air. None of the bleed screws or banjo fittings were designed to catch the spilt fuel. Finally I installed a bleed system which you can see in my video. Maybe I'm just lucky but since having installed this system I have had the engine shut down due to air but have NEVER had to vent from anywhere except through this system. If/when I change the engine filter I will simply keep the bowl slightly loose and then prime until fuel leaks out of the threads. https://youtu.be/H-GI38vE4hQ?t=2m13s Now to answer your questions: 1) What micron rating filter? - I'd refer you to the owners manual. The majority of bearing were comes from particals smaller than 5 microns and those parts don't have exacting tolerances like the HP pump and Injectors. As stated above, IIRC the yanmar primary filter part is 2 micron. 2) Are there better new designs? I see Racor have spin-off models. Are these easier to change and bleed on the fly? - I don't know any of the marketing reasons but I like the Racor 200 or 500 series that have a clear bowl. This allows tou to see if air/water/dirt is accumulating. 3) Should I have primary and secondary filters? - IMO yes. If you have room you can go one step further and have a standby filter in parallel. If it looks like a clogged filter is the problem for your shutdown then you simply shift filters. You can change the dirty one later, at the dock, in calw seas. 4) How best to bleed the air? - Do what you can to fill the filter media and bowl most of the way even if that is just simply pouring fuel in the bowl and then attaching the bowl. 5) The Westerbeke W33 manual says it's self bleeding and essentially not to mess with the pump. What do you know of this? - It would seem that while I have manufacturers recommended vent points, they are not needed. In my case, more vents and better venting just means less cranking. To that end, if you simply placed a dry filter in the housing and hoped that the engine would self vent you'd probably find yourself cranking for a considerable amount of time. Besides just because the engine is self venting doesn't mean that the filter is. Josh Muckley S/V Sea Hawk 1989 C&C 37+ Solomons, MD On Jun 30, 2017 7:54 AM, "Damian Greene via CnC-List" <cnc-list@cnc-list.com> wrote: I have some questions for your collective wisdom: what is the best fuel filter setup? First of all, I have to admit I just bought a Sabre 38 (1986). We are en route home from Essex CT to Bass Harbor ME. We were going through fairly rough seas yesterday entering Buzzards Bay and the engine died - backed off on revs over a minute or so, then stopped. Restart would not go to high revs, and died. I figured it was the fuel filter, but we took a TowBoat US tow into New Bedford rather than mess around. I changed the filter and all seems fine. The filter is a Racor 2010. Engine is a Westerbeke 33. Diesel tank was half full. It turns out the PO had installed a 2 micron primary (there is no secondary). It looked fine - so no major crud. I have a 10 micron installed now, as I had a couple of these as spares. The local yard recommend 30 micron. I could not figure out how to bleed the air, so I filled the housing to the top with diesel, and poured more in the top before inserting and tightening the top screw. I would not fancy doing that in rough seas. So questions: 1) What micron rating filter? 2) Are there better new designs? I see Racor have spin-off models. Are these easier to change and bleed on the fly? 3) Should I have primary and secondary filters? 4) How best to bleed the air? 5) The Westerbeke W33 manual says it's self bleeding and essentially not to mess with the pump. What do you know of this? Thanks, Damian Damian Greene 1982 C&C 34 Ghost (for sale) 1986 Sabre 38 Serenity (new name TBD) Bass Harbor ME _______________________________________________ This list is supported by the generous donations of our members. If you wish to make a contribution to offset our costs, please go to: https://www.paypal.me/stumurray All Contributions are greatly appreciated!
_______________________________________________ This list is supported by the generous donations of our members. If you wish to make a contribution to offset our costs, please go to: https://www.paypal.me/stumurray All Contributions are greatly appreciated!
