Carbs

[Barry20383]

Have fitted a new rotor arm from the club spares a red one. I can put the old one back and give it a try .

[BarryCambs]

If it doesn't fire at all, it might be worth double checking the firing order if the leads have been changed. We've all been there!

[Barry20383]

Will have to check everything start from scratch. It has run since changing the leads. The new leads have supervisors built in don't know if that would reduce the spark. Spark seems ok.

[BarryCambs]

The suppressors shouldn't be an issue, but some coils are very sensitive to having the polarity reversed. With a new coil and everything else you've replaced, the spark should be very healthy and jump 10mm. I've got caught twice with new faulty condensers which left the cars unable to start after a service and a single cylinder generator with a faulty NGK spark plug. The first new coil I got for the Long Two when we were originally recommissioning it had such a weak spark it wouldn't start. Each times it taken me a while to sort the problem, as you immediately rule out anything you've changed for new!

[Barry20383]

Have connected the + on the coil to the dizzy as the car is positive earth. I have a spark gap tester somewhere will sort it out and check the spark strength. I can test the condenser with a meter to see if its shorted and also disconnect it as its only to stop the points getting burnt so it won't harm to try once.
Will have to start from scratch and hope i find it as it is getting frustrating would like to get it on the road and then renovate it. Have already completed the brakes new cylinders at the back new seals at the front new shoes all round .
Hope i can get it running i did have it running but not well that's why i changed the carbs as the choke spindles were worn.
Thanks again Barry.

[Keith Clements]

A lot of chat over the last day and hard to keep up with it....so the loss of suction was the gasket as I advised.

I can understand your frustration at turning a car which ran, into one which does not, by changing the carbs for renovated ones.

You seem to have all the required diagnostic kit so apply a good methodology and the problem should be found.
Ignore everything you think you have done. The Jowett patient topic should help.

The choke spindle wear would make little difference to running, either slow idle or full bore. They would need to be severly worn to affect starting which was not the problem any way.

If you change something, inspect it to see if it is the same as the original. If the change does not fix the fault replace the old component and check the situation is the same as before. Replacing with new often introduces new faults.

Poor idling could be a number of things.

[Barry20383]

I checked all the obvious things and found that there was an air lock in the fuel line which might be caused by the modern fuel filter none original
Took of the petrol pipe and pumped fuel till no air was present turned the engine over on choke and it started first time and ran sweetly.
However it started to get lumpy after five minutes and stopped. On checking found fuel leaking from both carbs .Took out the plugs and found them black and sooted up perhaps due to flooding. I have 2.5 spacer washers under the needle valves i could increase to 2 and try it
The slow running jets are set to 2 turns out as instructed as the start point in the manual.
At least with the engine starting that eliminates a lot.
Thanks for any advice Barry..

[Forumadmin]

I think this is where the thread started - fuel leaking from the carbs.
All the advice previously given still applies.
Check petrol pressure.
Check pump pressure cut off.
Close needle valve with finger.
Check petrol level in float chamber.
Check float chamber gasket.

[Barry20383]

The original leaks were caused by the re con carb emulsion block gaskets being fitted upside down the cut outs were at the bottom the gaskets were damaged by the screws. Due to this new gaskets were supplied by the Jowett spares. This leak has now been solved.
It appears the leaks now from the back of the bowl seems to be flooding. If the level in the float chamber is too high can fuel overflow and run down the emulsion block as there is no gasket between bowl and body of carb.

[Forumadmin]

There must be a (horizontal) gasket between bowl and carb body. There is no gasket on the vertical face.
But it probably should still not leak when just pumping manually, just the mixture would be completely screwed and possibly leak when running.

[Barry20383]

Am still having problems i did manage to get the engine running and it started twice first time it was hunting a bit as it needs the recon carbs set up.
Have tried to start today but am getting nothing not even a kick.
Have checked spark and fuel air locks still nothing.
Have tried suction on each carb with balance gauge with choke off drivers side showing 6 passenger side nothing .If only one carb suction i would think engine would fire on one side or get a kick.
Can the balance pipe be causing a faulty reading.

[Keith Clements]

The balance pipe connects the two inlet tracts. If it has a mouse stuck in it then it might cause problem .
Rather than your gauge put your hand over the inlet and feel and listen. The gauge only works when the engine is running .
Have you gaskets now above bowl tops?

[Barry20383]

I used the carb balance meter with the engine turning over on the starter motor to check suction.
Have fitted new gaskets to the bowls.
I started it twice yesterday and it seemed to run ok. I was going to start it today let it warm up and make the adjustments for running smooth.

[Nick Webster]

I am a bit puzzled about all this talk of measuring suction with what sounds like a flow meter gauge. Also, you will not get an accurate flow reading at the slow and erratic speed the starter turns the engine. There has been mention of the balance pipe between the carbs but has the pintle valve been checked for cleanliness and correct operation? This will affect carburation.

Nick

[Keith Clements]

Suction ...consider firing order

Agree with Nick.

Check both butterfly valves are fully closed when on throttle stops.
Pull out choke fully , check 2mm approx gap now at throttle stops and both choke butterflies fully closed.
Manually pump petrol listening to hear squirting through needle valves.
Check squirting stops when float chambers full.
Press starter.
If it starts , stick a length of tube in your ear and listen for hissing around base of both carbs and under oil filter and around pintel valve.
Use same tube to check for even hissing at carb inlets.
Release choke gradually and check engine keeps going.
When warm adjust idle speed using tube in ear on both carbs.
Then adjust idle mixture if required. A quick check can be done by momentarily placing hand over carb when engine should speed up then slow down. But then adjust as per book.