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<font size=3>The '73 MGB should have JIF carburetors, carbon canister and
anti-run-on valve (also air pimp and gulp valve). If ll is in
place, the ARO valve should prevent run-on when switched off. With
backfire and low power at road speed, you may have a vacuum leak of lean
fuel condition. Tell us what is not installed exactly as
original. Has the throttle valve poppets been soldered shut?
Missing air pump or gulp valve? Missing of disconnected carbon
canister or ARO valve? Is distributor vacuum advanve
working?<br><br>
<br>
At 08:10 PM 11/30/2021, dave northrup wrote:<br>
<blockquote type=cite class=cite cite="">....<br>
Haven’t had it too long. Seemed to be running ok; had transmission
problems so we swapped out for a good one.<br>
<br>
Just had a very knowledgeable friend set the timing and the carbs and the
choke adjustment.<br>
<br>
Pull the choke all the way out and it starts ok; but seems to backfire a
bit, especially when cold. After it warms up you can push the choke
back in and it runs and idles ok except it seems to have a loss of power
in the 3000 + rpm range, and does occasionally still backfire.<br>
<br>
Has a Pertronix but other than that seems pretty stock including the air
pump. Tends to run on a bit after you turn it off.<br>
....</font></blockquote></body>
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