As per earlier is it in the return or feed?

If return then your bowls are full, Just when you looked under bonnet?

J
 
I'd expect to see a filter in the feed line to remove anything before it affects the jets etc, can't see a lot of point in having it in the return line.
 
You seem to have done everything you can yourself and double checked it to no avail...if it was me I would consider dropping it off at a garage and get them to check it out...I'm not questioning your ability just sometimes a fresh pair of eyes makes all the difference.

Rob
Hi Rob
Yes mate I’ve got to that point after last night
 
I'd expect to see a filter in the feed line to remove anything before it affects the jets etc, can't see a lot of point in having it in the return line.
No all the filters were in place the extra filter on the supply was purely just to see if there was fuel at the point of cutting out
 
I did suggest that at the start..possible inlet manifold leaking when at temp...@marjon...
Yes you did mate I did check with a stethoscope for noise and couldn’t find any do you think it’s uncheckable so replace it anyway?
Need to read all that in the daylight :eek:
Sounds like you have done a bunch of testing and there maybe something in there.

A fresh pair of eyes may help as @Shippers suggested do you have a mate/friendly mech? Is there anybody with a V8 near you on LZ? Got to be.

I really can’t see what we are missing:mad:.

Is the filter on return or feed?

Something is breaking down under load, to me that is spark plugs and work back. Or coil and work other way.

Or a big vac leak under load? Thoughts?

Don’t give up:)

J
Replacing valley gasket not done yet I will order a new one today. Yes I’ve got a mate who’s a good mechanic and it’s stumping him. The filter was on the feed just so I could see everything was ok when it cuts out.
 
@Shippers has your SU got the extra fuel swirl pots on the side of your carbs?

Now I know there is/should be a restriction for the return could this be blocked off to ensure the bowls are full of petrol?(restriction is in 1 of the brass joints)

If you have a facet pump this may stop as there is a pressure valve in them.



This problem is still stumping me.
 
The SUs work on a low pressure if you block the return chance are the pump would just overcome the float valve and pump it straight into inlet.

If I remember we went over all this earlier (there’s been so much).

It would be good to see that filter full when engine running though.

@Muddy goose did you ever get a video of it running and cutting out?

Running low on ideas now:(

J
 
20190629_110827.jpg
20190629_111119.jpg
I have zenith carbs...supply goes to LH then across at the joint at carb to RH where it is reduced down to narrower pipe to return to tank this is original set-up.
20190629_111130.jpg


Pics show external pump which supplys direct to glass sedimenter\filter then across to blue canister filter then to carbs these are full all the time....the only non standard part of set-up is external pump....
 
View attachment 182635 View attachment 182636 I have zenith carbs...supply goes to LH then across at the joint at carb to RH where it is reduced down to narrower pipe to return to tank this is original set-up.View attachment 182637

Pics show external pump which supplys direct to glass sedimenter\filter then across to blue canister filter then to carbs these are full all the time....the only non standard part of set-up is external pump....
Hi Yes that’s how I had mine before whilst still having the issue so changed made since and during the issue. I was finding that the LH swirl pot had less fuel than the right hand side hence putting a t joint in the middle of the two to supply both carbs the same amount. No it didn’t cure it
 
I must say again the same as the SU carb man said the cut off is not fuel as it just stops no coughing or spluttering I will try and take a video
 
those filters never fill fully and be best down stream on its side, presumably youve fitted a new coil and or dizzy amp they are the 2 things ignition wise that spring to mind of engine dying after it warms up
 

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