Yanmar 4JH4AE fuel filter replacement

[Hillard]

I have a 4JH4AE in my 2008 DS42. Last week I experienced a very dangerous engine failure. I was making way under power to a narrow harbor entrance in a 20-25knt crosswind. Just as I was about to enter the channel, the engine died. I was able to unfurl the main a little bit in time to avoid being blown into the shouls on the side of the channel.

Manuvered outside of the entrance and tried restarting the engine to no avail. It would run for 30-40 seconds and then die. Lots of possible contributing factors to consider as I had just filled the diesel tank the day before. Potential water intrusion or debris in the new fuel or a failed fuel pump or clogged filters. We had run the engine around 30 minutes total after the fill.

Could not get the engine restarted, so we anchored and rode out the night in a20-25knt wind. Next morning had Seatow take me into the harbor.

I ended up replacing, one at a time, the prefilter , the fuel pump and the final filter. None of the filtes appeared dirty and no water was everident. We’re leaning towards the fuel pump as the culprit. It just went out at an inopportune time.

However, this process convinced me to replace the stock Jeanneau water separating filter under the master bed with a Racor filter with a priming pump. I’ll also relocate the filter to the engine compartment.

Has anyone done this? What issues did you run into? Where did you plumb the fuel return line from the injectors?

Thanks,
Mark

Read more: Yanmar 4JH4AE fuel filter replacement | Jeanneau Owners Forum

[jmorrison146]

Did this swap a year or so ago. Will get you the details shortly.

[jmorrison146]

[jmorrison146]

Mounted the smallest Racor, 500MA, to the starboard side of the aft engine space bulkhead. Cutoff valve facilitates filter swaps.

[Hillard]

Where did you route the return fuel line? The stock Jeanneau water separating filter has the return line and the fuel tank line in on one side and the output to the fuel pump.

If I get rid of the original filter, I need to either return the fuel to the tank or put a T on the racor input side.

[CarlF]

If you can squeeze it in, get twin Racors with a valve to switch over. Equip the one you run on normally with both a pressure gauge and a water sensor to alert you to bad fuel. Then throw the valve to have a clean filter. Mount it somewhere that's easy to change too.

With this setup, I ignore Yanmar's rule that the Racor should be 30 micron. I put in a 2 micron. I've gone 1500 hours with no problems (4JH4HTE). On my boat the Yanmar filter is very hard to change at sea. With the 2 micron Racor's the Yanmar filter is always clean. I change it every other year just to be conservative.

I expected the 2 micron to clog quickly but it hasn't happened. Maybe it would with 400hp powerboat engines. These filters are rated for 60gph. I'm doing 2gph. With only one exception, I've always gone 200 hours between changing the Racor filter which I do whenever I change the oil.

[steve77]

I had a mechanic in La Linea, Spain (Gibraltar) act all surprised when I told him it’s common to use 2 micron filters in the US. “You must have really bad fuel there” he said.

What a silly statement. If we had bad fuel, the 2 micron filters would foul immediately. With good fuel, 2 micron filters work great.

Cheers!

Steve

[daletournier]

You can also add a little facet 12v pump inline, in such an emergency just flick a switch and your away. It will temporarily solve vacuum problems, fuel pump problems, partially blocked filter problems etc.

Personally I think 2 micro is a little overkill in the racors, I do run 10 micron, but that's just my opinion.

[MartinR]

The first thing I did when I bought my boat was to install a Racor filter. A rather big one, they do not clog so easy. 10 Micron is perfectly OK. The return from the injectors is directly routed back to the tank. I do not like to route this back into the filter, because the fuel gets warmer, loss of efficiency.

Fuel pumps normally do not fail catastrophically. Maybe you have a clog in the pickup in the tank or a fuel hose. Injection pump may also be a culprit, or the stop solenoid, or the governor.

[CarlF]

The reason I go with the 2 Micron is that the Yanmar filter on the engine is about 5 microns and located in a hard spot to change at sea.

I once got some bad fuel in Bahamas that left me with a max 1100 RPM at night in mid Gulf Stream. The 10 micron Racor was almost clean and the vacuum gauge on the Racor was fine. Somehow the fuel had a contaminant that was smaller than 10 micron but bigger than the 5 Micron Yanmar filter.

[onewadd]

I know this is a bit of a drift from the main topic but I felt compelled to respond again about the use of a 2 micron primary filter. I also know this will fall on some deaf ears but there may be some that don't know and take the 2 micron advice to heart.
I am a retired ASE and GM certified Master Tech in many areas including Diesel Engines. All manufacturers of diesel engines advise against using a 2 micron primary filter as both unnecessary and restrictive. The secondary filter (the one on the engine) is a 10 micron filter on all engines with the exception of common rail high pressure engines that are just now finding their way into sailboats. The GM DuraMax diesel, on which I've had over 200 hours of training, uses a 7 micron filter (they only have one from the factory) and never had an issue. They don't last long with semi-clean fuel (12000-15000 miles) and generally go from running fine to low power in just an hour or two at end of life. I have cut open clogged filters and seen nothing but filter except the engine sure did. The 2 micron is likely to go from flowing to nearly not flowing the same way is the reason factory engineers advise against using them. Also, Racor gives the same advice. Leave your 10 micron secondary filter something to do (as it was designed to) and use a 30 or a large 10 micron as a primary filter. You and your diesel will both be happy.

[DeepFrz]

Originally Posted by Hillard

I have a 4JH4AE in my 2008 DS42. Last week I experienced a very dangerous engine failure. I was making way under power to a narrow harbor entrance in a 20-25knt crosswind. Just as I was about to enter the channel, the engine died. I was able to unfurl the main a little bit in time to avoid being blown into the shouls on the side of the channel.

Manuvered outside of the entrance and tried restarting the engine to no avail. It would run for 30-40 seconds and then die. Lots of possible contributing factors to consider as I had just filled the diesel tank the day before. Potential water intrusion or debris in the new fuel or a failed fuel pump or clogged filters. We had run the engine around 30 minutes total after the fill.

Could not get the engine restarted, so we anchored and rode out the night in a20-25knt wind. Next morning had Seatow take me into the harbor.

I ended up replacing, one at a time, the prefilter , the fuel pump and the final filter. None of the filtes appeared dirty and no water was everident. We’re leaning towards the fuel pump as the culprit. It just went out at an inopportune time.

However, this process convinced me to replace the stock Jeanneau water separating filter under the master bed with a Racor filter with a priming pump. I’ll also relocate the filter to the engine compartment.

Has anyone done this? What issues did you run into? Where did you plumb the fuel return line from the injectors?

Thanks,
Mark

Read more: Yanmar 4JH4AE fuel filter replacement | Jeanneau Owners Forum

Check that your fuel pickup tube is not clogged up. It could easily clog without any evidence showing in either of your filters. Easiest way to check is to inject air from a scuba tank into the fuel line at the filter. Remove fuel line and blow back into the tank. Another possibility is a clogged vent line. Best check that first.

[kmacdonald]

I never did understand why boaters love their Racors. They are messy to change the filter and are prone to gasket leaks. The spin ons are much easier to change, way less expensive, have much larger filter area, and are proven in the trucking industry.

[ccannan]

Originally Posted by kmacdonald

I never did understand why boaters love their Racors. They are messy to change the filter and are prone to gasket leaks. The spin ons are much easier to change, way less expensive, have much larger filter area, and are proven in the trucking industry.

Please provide examples.

[kmacdonald]

I use a Fleetguard FS1000 followed by a Fleetguard FF5320. There are lots of filter heads available depending on what size ports you want. The filter attachment in 1-14 UNS threads.

FS1000: https://www.amazon.com/Fleetguard-FS...eywords=fs1000

FF5320: https://www.amazon.com/Fleetguard-FF...eywords=ff5320

Head: https://www.amazon.com/Fleetguard-He...%3A+142784S%29

Equivalent WIX, Donaldson, NAPA, Baldwin, etc can also be used.