Petrol flooding.

[Barry20383]

Have recently fitted re con carbs and recon dizzy to my Javelin.
Have set the ignition to fire at TDC the engine is starting but the plugs are getting wet with fuel.
Is it possible the float jet washers are to small allowing carbs to flood or could it be another reason.
Thanks Barry.

[Keith Clements]

This seems to be a repeat of your previous topic on the subject.
The answer to your question is no.

Go through the tests previously explained and let us know the results.
How long was the engine left running? Let it warm up and run for 20 minutes. Check choke is fully open. Are all cylinders the same?

[Barry20383]

Have run the engine for 20 mins taken out the plugs and they are sooted. The drivers side carb started to leake fuel when the engine was stopped from the rear of the float chamber and the plugs on that side are sooted and wet.
Barry.

[Keith Clements]

Pump fuel manually and see if it still leaks. If it does not leak then it is likely the fuel pump pressure valve is not correct. If it does, it still may be the pressure valve, but now you can also check if the float valve closes when you put your finger on it. If it does then it could either be there is not enough float pressure to close it or the fuel pressure is too much. Weigh all the floats you have and pick the lightest. If finger pressure closes valve then check float can and does close valve. Maybe it sticks in bowl. Put another washer under valve.

If fuel leaks when your finger is on it then check the valve, washer and casting for leaks.

[David Morris]

Hi Barry,

I think it all depends on whether you have a mechanical pump or an after-market electric one? Everything Keith says about the float cut-off valve is correct wrt a mechanical pump. Check the washer under the valve, the condition of the metal and fibre washer, the condition of the float and finally the valve itself. Spares are available. The threads in the top of the carb may be worn as well?

If, like me, you have an electric pump, they produce far too much pressure and you need a reducing valve between the pump and the carbs. This should be set to the lowest pressure, no more than 1.5lbs/in. The clue with an electric pump is to see whether it 'goes on 'clicking' after you have switched it on and before you start the car? It should initially fill the bowls and then go silent, ready for you to push the button. If it goes on beating, after a couple of minutes, check for leaks immediately.

Take care,

David

[Keith Clements]

This is a long saga,
viewtopic.php?f=2&t=5844
we have been around most things already. So it may be time to swap out the fuel pump, as it is possible it is not delivering the correct pressure. But I have suggested a way of checking that.
I think bowls and complete carbs have been swapped but is unclear if the fault always remains the same.
Clear thinking and a systematic approach is needed with each step documented.

[Nick Webster]

There are forums throughout the Internet all dealing with the difficult question of solving some mechanical problem without actually seeing the car. This is never easy and discussions will race off on different theories. Time then to consider one of the strengths of the JCC which is the section areas where I am sure there will be at least one member who can be more hands on to help sort the problem. Local area Secretary should be first point of contact and they will know from the membership lists who has registered that they are willing to help. ( COVID willing ).

Nick

[Keith Clements]

Hear, here Nick.
Yes I have been thinking of holding another Technical day/weekend in my garage but instead will have to use our section Zoom meeting instead.
On Wednesday 19th May at 7pm the Southern Section will have their Zoom with Main topic :
Getting your Jowett back on the road after lock-down
- What to do
- What to look for
- What to avoid
- Other?
With a bit of computer technology you should be able to do a live demo of any problem and get the 'brains' to help!

This is the 2019 Technical Days topic.