Jeff Sharpe wrote:
>
> Hi list,
>
> Trying to track down a lumpy low idle on my '71 B that has eluded me for a
> long time. Seems like it would be a vacuum leak, but not sure. All ports on
> the intake are plugged currently (found the vac advance was shot today, so I
> disconnected it and plugged that port). I'm wondering about the remaining
> emission plumbing, and if it could be a factor. Air Pump and Run-On valve are
> gone. A 'Y' line from the carbs and a line from the fuel tank evap are both
> connected to the top of the charcoal canister. The large port on the bottom
> of the canister has a plug in it. The valve cover breather is not connected
> to anything. I tried connecting the valve cover port to the top of the
> canister, and unplugging the lower port - no change. I'm probably way off
> track, but I've been through the carbs, timing etc over and over. A clue may
> be that it runs rich, even if I lean out the mixture all the way (air cleaner
> off). By the way, carbs are orig HS4's, AUD 465, reshafted about five years
> ago (and slightly leaky), new needles/seats/floats. Looked at the needles
> today and they are both marked AAL. What am I missing?
Hope this isn't useless (long stretch): lift gently up and down on
the carb setup. Not hard enough to damage even a dodgy connection,
just a sort of gentle test of the gasket and manifold nuts. More
often than you might expect, it makes the idle speed go up and down
noticeably. This indicates an intake air leak.
It's proverbial in Minis, where radical situations can cause the
carb(s) to hit the rear bulkhead, but I have seen it caused on an
MGA when a #$%$#$ "mechanic" leaned his elbow on the front carb hard
enough to compress the manifold gasket. Results: two burnt valves,
one ruined seat, one holed piston. I assume the same would be
possible on a B.
-Rock http://www.rocky-frisco.com
--
Red Dirt Rangers (Rocky on piano): http://www.reddirtrangers.com
JJ Cale Live (w/Rocky): http://www.rocky-frisco.com/calelive.htm
The Luggage Fan Club: http://groups.yahoo.com/group/luggage-fans
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