Engine Bleeding

[Tony]

I have a Yanmar 4JH3E 56hp engine I am not getting the air out of after changing Racor and engine fuel filter.On top of Racor I have the one with a pump in it . What is the correct bleeding point. There is a white plastic slotted nut on the top and on the side is a hex brass nut. does one or both of these need to be pumped clear of air ? There is a bleed nut on top of engine fuel filter, where is the bleed nut on the injector pump ? I have never had a problem before but just can't seem to get this one right to get enginr stsrted.

 

[Don]

three steps

You might want to check out www.yanmarhelp.com for a more thorough description. In short,1. pump Racor with bleed screw cracked until you get fuel (bleed screw on top),2. crack top bleed screw on fuel pump adjacent to fuel filter and pump small handle on fuel filter until you get fuel, and last3. (only necessary in limited circumstances where you have air on high pressure side of injectors) take one turn on first injector and crank engine until you get fuel.The Yanmar site is far more descriptive.Don

 

[Phil Hunter]

Injector Block

Tony,I had the same problem. Sometimes after a filer change air can get trapped in the injector pump. This is usually right below the secondary filter. Their is a small screw on the top of it. Bleed the air off of this as you pump the manual plunger. This procedure is not in the book and air in the ejector pump can cause grief. Phil

 

[Baysailor2]

Three points to bleed

I just went through this same problem on my 3GM and a friend's two cylinder Yannie last week after regasketing the fuel lines. On these engines there are three points overall that you need to bleed. There are two bleed points on top of the primary filter. The first one to bleed is the one closest to the block on the inlet side to the filter (atop the line from the lift pump -- 10mm). The second one is the larger one on the outer side of the filter on the outlet side leading to the high pressure pump (12mm). The third is on the top of the banjoe bolt that attaches the fuel line from the filter to the high pressure pump (10mm). Once you get foam out of the third one and it runs solid fuel, flip the compression releases and spin the engine over for a short duration to prime the injectors. If one of the releases happens to flip back, don't be surprised if the damn thing actually fires up! Also don't forget to open the raw water ball valve if you closed it so that prolonged cranking of the engine didn't flood a cylinder. Use the Racor's bleed pump (unscrew the white knurled nut on the filter top and lift up), it moves much more fuel with each stroke.