Fuel problems

[MarkM]

A few days ago I was out with my boat and the Evinrude 250 DI. At 60km/hr and 4000RPM it was fine. Then suddenly RPM went down to 3000. After a while it was ok again. This went on for one hour or so. We changed the petrol filter (Delphi), dismantled the RVS pipe in the tank, had a good look at all the hoses, etc. Nothing wrong. When the engine stalled the computer in the Evinrude said: code 57 which is a fuelproblem. So at moments it's not getting enough fuel.
Today I was out again and the same problem occured. Fine for a period of time and then back to idle. After a few minutes everything is ok again. I noticed that during the problems the fuel ball went flat. So there is a vacuum. The ball is a new one with the yellow ring.
My questions: how can one test a fuel ball? Is there a need for a fuel ball with a new modern engine?

[BogMonster]

First thing I would check is the fuel tank breather, because if that is blocked or kinked it will cause a vacuum.

[MarkM]

The tank is 450 liters, filled with 250 liters. I took the filler cap off after the trouble but the problem was still there.

[firestopper]

hi mark check the fuel tank breather, it could be blocked,causing a vacuum,so when first started and run at harbour speed all is well, then when you open up it vacuums virtualy no fuel gets thru.when the problem occurs try undoing the fuel tank cap if it makes a whooshing type noise thats the problem more than likely. failing that it is possible you may have a collapsed fuel pipe internaly, outside can look fine but if the pipe breaks up in side a flap of rubber can drop with the flow of fuel and block the flow.try these first as they are cheapest options.failing the above check the fuel pump diaphrams there may be hole in it or it may have gone to hard to pump properly. hope this helps.

[codprawn]

Try running with the fuel cap completely removed - if the bulb/ball goes flat again it is obviously a blocked pipe between it and the tank or a squashed pipe - try pulling the pipe out a bit from the deck or wherever. Could also be a blockage in the tank.

Yes you need the bulb to prime the engine - unless you fit an electric pump in the tank like on cars - there's a thought!!!

[LURCHER]

Warer seperator may need checking!

[vince]

The ball is a new one with the yellow ring

Could you have perhaps put it on back to front? All i know is that they usually have a direction arrow on them, just a thought..

[MarkM]

Thanks you all for your thoughts.
Ball is in the right direction.
I did take off the fuel filling cap on our way.
I took out all the piping and checked.
I did check the waterseperator.
The flow meter is working.

[sparkey]

change the fuel bulb... From what I can understand from your posts you fitted a new fuel bulb and started developing fuel problems. Is it the correct bulb, each bulb type has a flow rateing ( Lts / Hr ). Just because it is the same physical size as the old unit this does not mean that it has the flow rate.

[quinquarimarine]

Originally Posted by MarkM

Thanks you all for your thoughts.
Ball is in the right direction.
I did take off the fuel filling cap on our way.
I took out all the piping and checked.
I did check the waterseperator.
The flow meter is working.

MARK

Some pointers

1. Primer bulbs can fail, even new ones = we find it necessary to check every one before fitting and also replace them at least every 2 years.
2. If the DI is showing a code 57 fuel fault and the bulb is going flat then it is probably on the delivery side and not the engine (incl the diaphram) unless you are pulling a high volume of fuel.
3. You need to check where the fuel flow transducer is fitted - it must be fitted after the delphi filter . I would not use this transducer as it can cause a restriction and if fitted before the filter is very prone to blockage.
4. have a close look at the Delphi filter. Most fitted to a standard Cav are rated at 90 litres and from memory the 250 DI as a single may require about 130 litre flow rate.
5. Be warned that running with starvation/restriction can cause significant powerhead damage.

I would be putting bet on filter/flow tranducer area. From that delivery hoses from tank to engine - they may look fine on the outside but check that the inner and outer walls have not parted. From there an itinerant bit of crap in the tank that works its way to the pickups every so often. You could fit a vacum gauge inline and check with the evinrude serice manual that it is within tolerance.

Cheers

John

www.quinquarimarine.co.uk