TR2/3/3A TR3 SU carb leak repair

[Adrio]

I rebuilt my SU carbs almost 20 years ago and now they have started to leak fuel out the bottom again. I was about to order new parts when I see the cataloge talks about O-rings (Moss #365-420) rather then cork as a "leak free" replacement for Moss #295-200.

Has anyone used these O-rings and do they work any better then the cork. I guess my other question is can these rings be sources from any local place to save wait time from Moss, but that would require knowing what the specifications are for those rings and I don't. Does anyone else?

 

[TR3driver]

I have used them, and they do seem to last much better than the cork replacements I'd been using. 20 years is quite impressive to me, I was only getting maybe 2 or 3 from the cork (with driving every day).

They do appear to be standard O-rings, but I also don't know the specifications offhand. Material is important as well as dimensions.

FWIW, there are also improved bowl mount washers available from Joe Curto; but I've not tried those yet.

 

[Adrio]

To be honest, I said I had rebuilt them 20 years ago. I failed to mention how long I have been procrasinating solving the leak So it is not so impressive once you know how lazy I can be! Oh and I did not drive the car for five of those 20 years (kids and wife and all that).

 

[MGTF1250Dave]

Aloha Adrio,

I've used the o-rings several times when rebuilding SUs. I got mine from a local supplier of o-rings. Usually companies that sell bearing, seals, etc. will have o-rings also. I can't remember the size, but the OD would be interioir diameter of the jet bearing and the ID the outside diameter of the jet assembly. Let the supplier know you will be using the o-ring in a gasoline, gasoline-ethanol application so they can advise you of the right type to get. They provide a good seal and do not dry out like the cork does.

 

[eschneider]

anyone found a good rubber replacement for the large cork seal at the bottom of the jet assembly? I tried a standard o-ring which failed miserably.....

 

[Guest]

Of course! O-rings will work much better than cork... all modern cars/trucks use them extensively throughout the fuel systems.

 

[TR3driver]

I've always just used cork, which has worked quite well in that location for me. Don't think I've ever seen one leak, except on a friend's car that didn't have the nuts tightened properly.