Since you had head work done, I'd check for a sticking valve. If the
valve guides are too tight, one of more valves could start hangine up as
the engine warms up and the clearance gets tighter.
The symptom is similar to what you are describing and typically leads
one to check fuel and ignition issues to no avail.
> -----Original Message-----
> From: firstname.lastname@example.org
> [mailto:email@example.com] On
> Behalf Of Robert J. Guinness
> Sent: Monday, June 09, 2008 1:13 PM
> To: MG List
> Subject: [Mgs] Power Fade and Recover
> After replacing my cylinder head, rebuilding the carbs,
> adjusting the valves, re-timing the engine, balancing the
> carbs, and adjusting the idle, I get a power "fade" after
> about 15 minutes of driving. The car runs rough (no backfire
> though -- just a loose "fluffing" like sound as if its
> missing a few beats with no power for a few minutes. Then,
> all of a sudden, it will roar back to a tight, finely tuned
> I assume it is a fuel delivery problem. Where do I start the
> diagnostics? The car is a 1960 MGA with a 1963 MGB 1800
> engine and the original MGA carbs.
> Also, where can I search this list's archive. The link to
> www.listquest.com says the domain name is for sale.
> Thanks in advance.
> Robert Guinness
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