Leaky Dellortos

[zarelan]

Here is a question for carburetor experts, particularly those with Dellortos

In the 3 years I've had my Sprint, I've never had a problem with the Dellortos. But recently I've been a bit worried about the petrol moisture that seems to gather in the underside. Not dripping, but certainly moist with you wipe with your hand.

So last week I decided to make use of that service kit I bought months ago and overhauled them. Cleaned everything, replaced all the rings, needle valve, and gaskets. Put it all back, re-tuned them and I thought, that's that. Easy. However, when I checked them for leaks the following day, I noticed the same slightly wet area around the pump housing cover that I had before.

I have removed them again to tighten the cover screws a bit more, this time checking for leaks by filling them with fuel on the workbench. That has made some difference, but I still notice moisture when I run my finger along the gasket line.

Now I'm thinking that perhaps these bottom cover gaskets are supposed to look and feel 'wet' when the carb is full of petrol, and this may actually help to seal the joint. I'd rather see a bone dry joint as I am as paranoid as everyone else is here about fuel leaks, but I may be worrying about nothing.

Anyone with Dellortos has experienced the same?

--Antonio

[ppnelan]

No, but I have the same thing with a 'newly-rebuilt' set of Strombergs. The fuel sometimes leaks out quick enough to make a small wet patch on the fibreglass below when left overnight. It appears brown & waxy i.e. mostly dries up on the carburettor bodies. It is probably also the reason why it takes a while to start after being left for a week or more - not enough fuel in the float chambers? I have yet to try to fix it but it certainly looks like the gaskets are porous...
Perhaps some sealant/jointing compound would help?
I assume the fuel level is supposed to be above the gasket joint i.e. check the float levels are set correctly...

Matthew

[jimj]

Did you replace the diaphragms? The tiniest, tiny, little, tiny hole could be the problem. Jim