Bleeding a Beta 43

[Alway Swilby]

Twice now when I've changed the fuel filter on my Beta 43 I've had problems bleeding the system. I'm wondering if I'm doing something wrong. Here's what I do:

 

Turn off the fuel cock from the tank.

Unscrew the old filter, saving the diesel into a clean chinese takeawy tray.

Screw on new filter hand tight (having smeared the seal with diesel)

Undo the bleeding nipple on the fuel filter housing

Pump the button on top of the filter housing, bubbles appear from the nipple after a few pumps. Continue pumping and bubbles turn to foam. Continue pumping until no foam just clear fuel is coming out.

Tighten bleeding nipple.

Turn on fuel cock.

Start engine.

 

Then the fun starts. The engine fires up and runs for a few seconds then starts to slow down and eventually stop. Re-prime the filter and start the engine again. If I pump the button on the fuel filter when the engine starts to slow it recovers for a few more seconds then starts to slow again. So I pump again and it recovers again. I have to do this pumping for about five minutes until the engine runs properly. Is this normal?

 

 

 

[mrsmelly]

You need to turn fuel cock on as soon as you fit new filter and before priming.

Do you not have the electric lift pump fitted?

[Alway Swilby]

1 minute ago, mrsmelly said:

You need to turn fuel cock on as soon as you fit new filter and before priming.

Oops, yes, I got that in the wrong order. I do do that.

[mrsmelly]

2 minutes ago, Alway Swilby said:

Oops, yes, I got that in the wrong order. I do do that.

Yes I thought you must. On my beta the lectric fuel pump used to self prime anyway. I used to howver fill the new filter with oil and carefuly screw it on. Sometimes you need to crack a pipe after the filter anyway to expel air.

[john6767]

Ours is a Beta 35, but same setup.  I do exactly what you do and when starting it will misfire and run rough for 5 seconds or so and then is fime.  Ours also has a pre filter/water separator and I clean that out at the same time, and bleed that first by gravity, before bleeding the on engine fuel filter using the priming pump on the housing.

[Alway Swilby]

1 minute ago, john6767 said:

Ours is a Beta 35, but same setup.  I do exactly what you do and when starting it will misfire and run rough for 5 seconds or so and then is fime.  Ours also has a pre filter/water separator and I clean that out at the same time, and bleed that first by gravity, before bleeding the on engine fuel filter using the priming pump on the housing.

Yes, I also have a pre filter water separator which I normally do before the engine filter,  then as you say bleed by gravity. If I only do the pre filter then I have no problems.

[Alway Swilby]

22 minutes ago, mrsmelly said:

Yes I thought you must. On my beta the lectric fuel pump used to self prime anyway. I used to howver fill the new filter with oil and carefuly screw it on. Sometimes you need to crack a pipe after the filter anyway to expel air.

I don't think mine has a electric pump, I think it's mechanical. The engine was supplied in 2016. My old Barrus Shire had electric pump and self primed without any bother. I liked that engine but it smoked a bit.

[Keeping Up]

You don't need to open the bleed nipple. The button on top of the filter not only pumps fuel, it also expels the air. So after replacing the filter, just turn on the fuel and then pump it until the feel of the button changes to showing no resistance, then start the engine. It may falter slightly but it will keep running.

[Alway Swilby]

2 hours ago, Keeping Up said:

You don't need to open the bleed nipple. The button on top of the filter not only pumps fuel, it also expels the air. So after replacing the filter, just turn on the fuel and then pump it until the feel of the button changes to showing no resistance, then start the engine. It may falter slightly but it will keep running.

Thanks. I'll give that a try in 750 hours!

[Jen-in-Wellies]

On 06/05/2019 at 21:17, Keeping Up said:

You don't need to open the bleed nipple. The button on top of the filter not only pumps fuel, it also expels the air. So after replacing the filter, just turn on the fuel and then pump it until the feel of the button changes to showing no resistance, then start the engine. It may falter slightly but it will keep running.

This works for me too. I also fill the new filter with clean diesel before screwing it on to the housing. This saves time pumping out the air as there is a lot less air to pump.

 

Jen

[nicknorman]

There is an automatic air bleed valve on the injector pump on our Beta 43 (2010) - basically a float which sinks when there is air, opening a path for the air to escape, and then when the fuel level rises, floats up to block the air exit. There is also a manual knob which can shut off the air exit permanently. So it is important to ensure that this valve is left open (anti-clockwise). It takes the form of a small knurled knob on the injector pump block.

 

If this is closed, using the prime pump will clear the filter and pipes of air, but it won’t get rid of the air from the interstices of the injector pump.

[WotEver]

Oooh... interstices... it’s Big Word time again...

[Alway Swilby]

9 hours ago, nicknorman said:

There is an automatic air bleed valve on the injector pump on our Beta 43 (2010) - basically a float which sinks when there is air, opening a path for the air to escape, and then when the fuel level rises, floats up to block the air exit. There is also a manual knob which can shut off the air exit permanently. So it is important to ensure that this valve is left open (anti-clockwise). It takes the form of a small knurled knob on the injector pump block.

 

If this is closed, using the prime pump will clear the filter and pipes of air, but it won’t get rid of the air from the interstices of the injector pump.

I'll have a look for that next time I'm in the engine bay. Thanks.

[Alway Swilby]

On 08/05/2019 at 09:55, nicknorman said:

There is an automatic air bleed valve on the injector pump on our Beta 43 (2010) - basically a float which sinks when there is air, opening a path for the air to escape, and then when the fuel level rises, floats up to block the air exit. There is also a manual knob which can shut off the air exit permanently. So it is important to ensure that this valve is left open (anti-clockwise). It takes the form of a small knurled knob on the injector pump block.

 

If this is closed, using the prime pump will clear the filter and pipes of air, but it won’t get rid of the air from the interstices of the injector pump.

Found it and it was screwed shut. I've had the boat from new so either Beta ship them out closed or the engine fitter left it that way. Is it ok to leave it permanently open?

[Alway Swilby]

On 08/05/2019 at 09:55, nicknorman said:

There is an automatic air bleed valve on the injector pump on our Beta 43 (2010) - basically a float which sinks when there is air, opening a path for the air to escape, and then when the fuel level rises, floats up to block the air exit. There is also a manual knob which can shut off the air exit permanently. So it is important to ensure that this valve is left open (anti-clockwise). It takes the form of a small knurled knob on the injector pump block.

 

If this is closed, using the prime pump will clear the filter and pipes of air, but it won’t get rid of the air from the interstices of the injector pump.

Update: 750 hours later I've changed the filter again today. I made sure the knob was open (it was shut last time) and sucessfully bled everything. Many thanks for that tip, worked a treat.

[nicknorman]

Jolly good. Just to answer your penultimate post which I must have missed, yes you can and should leave the knurled knob open permanently.