Priming bulb

[Vinny31]

I’m chasing a bit of a fuel starvation issue at high revs since my engine was serviced a while back.
Boat runs fine on auxiliary tank however on the inboard tank I get this issue.

To this end I’ve replaced the fuel hose from tank to engine, fitted new priming bulb etc.
My question is should my priming bulb go hard when I pump it then stay hard when the engine is running?
Presently it’s doing neither leading me to believe I may be drawing air somewhere.
Thanks

Gavin

[Pikey Dave]

Originally Posted by Vinny31

I’m chasing a bit of a fuel starvation issue at high revs since my engine was serviced a while back.
Boat runs fine on auxiliary tank however on the inboard tank I get this issue.

To this end I’ve replaced the fuel hose from tank to engine, fitted new priming bulb etc.
My question is should my priming bulb go hard when I pump it then stay hard when the engine is running?
Presently it’s doing neither leading me to believe I may be drawing air somewhere.
Thanks

Gavin

It should go firm when you pump it & go softer in use but still hold its shape, but it shouldn't collapse.(oooer matron) you might have some crud in the main tank that is blocking the pickup, but this would cause the bulb to start to collapse. You don't say what your symptoms are, can you give us more info?

[Erin]

I had something very similar which turned out to be some debris partially blocking the inlet barb on the fuel filter/water separator. Once this was cleared all was good. I’d suggest you disconnect each joint in the fuel line and check for blockage.

[Vinny31]

Originally Posted by Pikey Dave

It should go firm when you pump it & go softer in use but still hold its shape, but it shouldn't collapse.(oooer matron) you might have some crud in the main tank that is blocking the pickup, but this would cause the bulb to start to collapse. You don't say what your symptoms are, can you give us more info?

Hi Dave, symptoms are that it will only take full throttle for a few seconds then starts to die. Nearly put me through the screen first time it happened, if I throttle back it will pick up again.

Will run up to around 4K revs without issues.

I’ve run it on a separate tank and it was grand. Hence replacing full fuel pipe work and bulb etc.
I’ve removed the filler cap while underway and not had any suction so am sure it’s not air locking.

I’m thinking of changing the water separator then everything will be new[emoji848]

[Pikey Dave]

Certainly sounds fuel tank related. Does your water separator have a clear bowl? If so, any crud in it? Where's your bulb in relation to the filter/separator. You might have a dodgy outlet valve on the primer bulb. I've just had to change a not very old genuine Suzuki bulb that fell apart inside.

[Vinny31]

Yes separator has a clear bowl, no crud or dirt/ water evident. The bulb is before the fuel water separator and is new. Filter on separator is also new at service.
Might pull the lift pipe from the tank tomorrow and check the gauze to try and rule it out.

[Pikey Dave]

You say this has only happened since the service, have they fitted the new filter correctly? Not missed a seal out or got one badly seated. Is the filter screwed on (hand) tight?

[jeffstevens763@g]

If you have had the filter bowl apart the O ring might need replacing air getting in there.

[Vinny31]

That’s a good point, I’ll pull it off tomorrow and have a look.
Is it possible It may draw air without leaking fuel?

[Pikey Dave]

Originally Posted by Vinny31

That’s a good point, I’ll pull it off tomorrow and have a look.
Is it possible It may draw air without leaking fuel?

Not normally, especially as your primer bulb is before the filter, so pumping the bulb should pressurise the filter, but stranger things have happened & its one more thing to rule out.

[Vinny31]

Appreciate the help, thanks. I’ll let you know when I get to the bottom of it [emoji106]

[JimRib]

How are you connecting your aux tank to the engine ?

[Vinny31]

Originally Posted by JimRib

How are you connecting your aux tank to the engine ?

Direct, straight onto fuel intake.

[JimRib]

You could try the aux tank onto the filter to see if it’s that or your tank pick up

[Vinny31]

Originally Posted by JimRib

You could try the aux tank onto the filter to see if it’s that or your tank pick up

Sounds like a plan [emoji106]

[jeffstevens763@g]

Originally Posted by Pikey Dave

Not normally, especially as your primer bulb is before the filter, so pumping the bulb should pressurise the filter, but stranger things have happened & its one more thing to rule out.

just done mine dave says always change O ring each time bowl removed reason is the pump will pull air even though the bowl is full if its a bad seal its part of the filter kit anyways thats a yam filter by the way.

[Vinny31]

Just to update, got the opportunity to run the boat for nearly an hour today on lough neagh ( first time since fuel pipe was replaced)
No more starvation issues, engine ran faultlessly, 47 mph in the shelter of the bay[emoji106]
Hopefully l can now start clocking up the hours with a bit of peace of mind.

Appreciate everyone’s time with comments and replies, thanks [emoji106]

[jeffstevens763@g]

Had the fuel pipe collapsed vinney out of interest

[Vinny31]

Originally Posted by jeffstevens763@g

Had the fuel pipe collapsed vinney out of interest

It had swollen as shown above, I presume it was from the original fit out.

I’m going to cut it open when I get the chance and have a look inside.

[jeffstevens763@g]

Ha didn't realise that was part of the line never seen that before cheers