• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Carburetor cork seal fitting trouble

Share this page

1

100DashSix

Jedi Trainee
Country flag
Offline
I am rebuilding an H-type carburetor from an early BN4 and am having some difficulty in fitting a cork seal into the metal ring that sits on the jet adjusting nut. Both the ring and the old seal are tapered to fit into one another; the included cork ring in my rebuild kit is not tapered at all, however. How is the new seal supposed to fit? Should the cork be soaked and somehow forced into position?

The seal in question is number 20 in the following link; the tapered metal ring is number 19.

https://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=28863

Anyone's experiences or advice on this would be appreciated. Thanks!
 
I recently rebuilt two pairs of H-type casrbs and noticed the same thing....I just soaked the cork ring in some scilcone lube and did my best to fit it, it never really fit the way I wanted it(it seamed a little two big?) but now the carbs have been installed and run almost daily for 3 months and I am yet to have any trouble so I assume that I did it right.

Zack
 
It is usually suggested to soak the corks in oil for a day or so to make them more pliable. Make sure that the dished side of the rings are facing away from the spring with the corks seated as well as possible into the dishes. The corks should fit slightly into the dished side of the metal rings. Under pressure of the spring the corks will form into the rings & seal to the sliding jet. The top cork bears against the upper jet bearing & the lower cork against the lower jet bearing.

There are optional "improved" O rings available to replace the corks, but I have found them to either not seal, or to cause so much friction on the sliding jet that it will not reliably return from it's choked (lowered) position. Properly installed corks should last a good long time.
D
 
Thanks for the advice..I'll try soaking the ring and then properly fitting it. The cork seems pretty fragile, so I didn't want to go ahead and do that without hearing it worked for others first.
 
Just a brief addendum to Dave Russell's excellent (as usual) answer. And that is to make sure that you tighten the nut until it bottoms fully. Leaving it less than will cause leaks and the jet to become uncentered and rapid deterioration of the cork.
Dave Porter
 
[ QUOTE ]
Just a brief addendum to Dave Russell's excellent (as usual) answer. And that is to make sure that you tighten the nut until it bottoms fully. Leaving it less than will cause leaks and the jet to become uncentered and rapid deterioration of the cork.
Dave Porter

[/ QUOTE ]
I just thought of one other item. Make sure that the sliding jet's outer surface is polished as smooth as possible. I would use "very" fine sandpaper like 1500 or crocus cloth. Any roughness or burrs on the jet will quickly damage the corks.
D
 
Back
Top