I ran my engine this afternoon and could hear what I can best describe as an occasional hiss, exactly like an occasional drop of liquid dripping onto a hot manifold. I checked for leaks on the engine but there aren't any, and I think I have traced the noise to the carb' mounting gasket.

Would that hiss if it was cracked I wonder? It's not a continual sound, but exactly as I said - it sounds like a drip hitting a hot pipe. I sprayed the gasket with WD40 and the hiss stopped momentarily, the bolts are tight so I just wanted to confirm my suspicion before I renew the gasket. Also what would be the 'symptoms' of a cracked gasket, as my engine is running fine apart from that?

Next bit, should the swan neck to torpedo join be sealed with anything? Mine is blowing a little and leaking exhaust condensation. I seem to remember one of my 2cv's had a rubber seal around this bit, or perhaps my mind is playing tricks (again).

Might not be cracked - the base of the carb might be warped slightly, assuming all the mounting faces are clean.

<thinks> There isn't a gasket on there, is there?
<checks ECAS> Ooh. So there is. Or should be. I've always just used a smear of goo.



Just a smear of exhaust assembly paste.

I might save that fix for a rainy day then as it doesn't appear to be causing any problems, the blowing exhaust joint I can sort out for now I think.

For exhaust joints use a smear of coppaslip, it works just as well if not better than exhaust paste, doesn't crack and isn't a total pain to get off. I didn't think it'd work when I was told to try it, but i wouldn't use anything else now!

Agree with Adrian about the carb gasket and block, I've had one with the tiniest fracture that caused all sorts of head scratching!

Old-Nail,
when assembling the joints between the swan neck, torpedo and tail pipe I wrap some insulating tape around the end of the pipe, then brush some coppaslip over the tape.
This not only seems to help seal the joint, but also makes life easier if you ever want to separate a joint.

Adrian,
from the factory, there weren't any paper gaskets fitted to either side of the carb insulating block, but it seems to be fashionable to use them nowadays.
I prefer to make sure that the base of the carb is flat, then a light coating of Red Hermetite on both sides of the insulator block does the rest.

ken.

Thanks folks, I'll try that little copper grease dodge it sounds a good 'un.

copper grease is fab it is meant a an high temp sealant too

always used it on barrel to head joint as well as manifold gaskets, exhaust joints etc. tho i never worry about the leak from swan neck to torpedo.

Sean

I read this yesterday, and I had my doubts. Then my crossbox blew out today so I thought I'd give copperslip a go when fitting the "new" one. I was still full of doubt, right up until the moment I turned the key, and found that it had worked beautifully!

Great idea. Exhaust paste is a pain in the arse, especially if (like me) you can't go near a tin of it without somehow getting it all over yourself . I'll get a tin of coppaslip for the next time I do exhaust joints.