Overhaul of SU Carbs

[bobhayne]

Having problems with E Type 4.2 which has little use until recently. Start is ok but running can be a bit rough at times and found what looks like fuel in the air inlet trumpet on the carb nearest the bulkhead. Don't think carbs have ever been touched and suspect diaphrams may be perished. So I want to remove the carbs to strip and inspect them but am quite dismayed as the carb attachment nuts are very difficult to access as are the 18 inlet manifold studs! What to do? take off carbs or remove them whilst still on inlet manifold? Really need advice from someone who has done this before as to the best method to get them off please! Thanks for any advice Bob

[iRS]

I've taken the carbs off many times as a complete assembly with the manifold. Its not too bad, it just takes a bit of time. You should be able to do it in about an hour. You will need to drain the cooling fluid. Some nuts you can get on to with a socket and extension, the rest you will need a ring spanner. There are a couple underneath that you need to do by feel. You'll also need to disconnect the choke cable and throttle linkage and vacuum pipe. I'm afraid I can't remember taking the carbs off the manifold in-situ. What carbs do you have? I assume SU. I'm not aware these have a diaphragm. I think that' the Strombergs.

[bobhayne]

Thanks for your prompt reply iRS, good to know its been done before with them still on the manifold. I mentioned diaphrams as I was referring to the jets which sit in the centre of a circular rubber (maybe other flexible material) disk - I simply refer to these as diaphrams
Carbs fitted are on F-in-laws E type Series 2, 4.2 and he says they are HS8s, I think they are probably HD8s but will get him to check. Will let you know what's happening as the work progresses.
Cheers! Bob

[iRS]

Sorry, you're right. I was forgetting about this part of the carb. Its been a while since I took one apart.
On that note, it would make a good topic for the magazine, so if you could take some photos when working on them and write something about it, that would be great

[piman]

Hello Bob,

they are HD8s if they have the diaphragm needles.

Before going to the work of removing the carburretors, have you gone through the settings especially the float chambers as that may be the source of the fuel? If the diaphram is perished and leaking the fuel will come form outside the jet, if the float level is wrong it will come from inside the jet, i.e. where the needle enters.

Alec