Chummy carburettor problems

[akharding]

Thanks John, this is very helpful. I am going to have another look at the car in the next couple of days and hope to report success.

[Dave Mann]

Out of curiosity I removed the slow running jet on one of our cars and fitted a 10 mm bolt in it's place, the engine would start and run but wouldn't idle, your slow running jet is blocked.

[Steve Jones]

Given the symptoms you describe I'll be surprised if it isn't a blocked slow running jet but, if it isn't, you'll have eliminated the most likely cause and can move on from there.

A procedure that works for me with 22 FZ/FZB carbs when putting the car away for any more than a couple of days or so is to leave the engine ticking over with the petrol tap closed. Leave it running until it splutters to a halt with no petrol. Then turn the ignition off and walk away. That seems to ensure that no residual petrol remains in the slow running tube jet as it's that that causes the blockage most often. Probably famous last words but I can't remember the last time I had a blocked jet on my SWB Saloon.

Steve

[Ruairidh Dunford]

A couple of cars that I've worked on this year, fitted with this type of carb, have shown signs of verdigris on the jets.

They did not run properly, until completely clean.

[akharding]

Clearing out the jet did the trick ! Many thanks indeed to Steve Dave and John for suggestion and info about the idling jet.

[Stephencrisp360]

Was just going to add that this thread reminded me to look at the carb on my ruby as she would only idle with the choke out 1 inch. And to my surprise there was a load of gunk the float was upside down and the jets were impaired or blocked. Runs much better now .. Thanks for the advice here

[Dave Mann]

Crikey the only time my fuel taps are shut is if I'm working on the fuel system.