Those were added on later carbs in an effort to cut down on emissions. It
probably won't do anything to the performance to leave them plugged. That
is essentially the way the earlier HS2s were shipped anyway.
From: email@example.com [mailto:firstname.lastname@example.org]
On Behalf Of David
Sent: Saturday, August 12, 2006 7:12 PM
Subject: Overrun valve
I'm rebuilding the carbs (SU HS2s) on my 69 spit and I found something
strange. The throttle plate has a spring valve in the plate. Maybe this is
normal for these but it's the first I've seen. The Weber carb manual calls
it an overrun valve. First question, what is this for? Second, someone
sealed them shut with what looks like JB weld. Why would they do this?
Should it be sealed or should I try to free them up?
David Gates (Popeye444@comcast.net)
1967 GT6 Comm#KC5188L, Engine#KC5598E
Undergoing full frame off restoration
1969 Spitfire Comm#FDU47651L, Engine#FK30801UE
Driver, rough but it drives and getting better every weekend
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