There has been some discussion on the list recently of Stromberg carbs,
and I thought I'd relate this trivial but interesting incident I had
with my 250:
For the past couple years my accelerator pedal would hang up or catch
sometimes when I went to pull from a stop. It was as though something
was hanging up the linkage. It happened infrequently, and I'd bump the
accelerator pedal while sitting at a stop light to get it past that
catch point. People thought I was revving the engine for a quick
take-off (who, me?) but I was just getting the pedal unstuck. On
investigation, I found the bushing, or bearing, that guides the
accelerator linkage through the firewall, to be missing. I figured
that was preventing the pedal from working smoothly.
Before I could get that replaced, the car was in the shop for other
work. When I drove away, after the first stop light the engine was
stuck at fast idle. I turned around, and went back to the shop. Turned
the car off and went in for the owner. He moved the linkage under the
hood, reached inside the car to start the engine. Idled correctly. I
left again. At the first stop light, it was racing again! Back to the
shop. The second time back, I left it running. And racing.
The butterfly inside the rear Stromberg was sticking. The screw holding
it in place loosens, letting the butterfly hit the side and stick. Well,
in driving, I'd get the rpms higher, the butterfly opened more, and on
the way back it would stick. Didn't happen when the car was started
from outside without depressing the gas pedal (and revving higher),
which is why I went back twice. And left the car to be fixed.
But, surprise! now that the carb is fixed, I also don't have the
accelerator stick when going from a stop. The butterfly seems to have
been causing that, too, when slipping the other way. While it felt as
though that catch was happening very near the gas pedal and surely in
the linkage, it was catching all the way up in the carburetor. It's a
tribute to that English engine and those carburetors that it never ran
badly with this problem, but my gas mileage sure has improved since
fixing it.
Like computers, part of the fun of Truimphs is trouble-shooting, and
often, with Triumphs, the real cause can be several feet away from where
it seems to be!
Pat Fischer
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