Dear Spridgeteers,
I've recently noticed that upon initial acceleration, my engine
(1275, dual 1.25" SUs) stumbles. Also, while sitting at idle, the
engine seems to "load up", with the rpms becoming lower and erratic.
Checking the carbs., I found that balance and idle were OK. I reset
the mixture by screwing the jets upwards until they were both flush
with the bridges, then down by two turns (12 flats). I attempted to
fine tune using the method of slightly lifting the piston and looking
for a change in rpm (a steady rise in rpm indicating too rich, an
immediate drop indicating too lean, and a brief rise followed by a
drop indicating just right). Doing this, I found that the front carb
was about right at only 6 flats down from bridge and the rear carb
was right at 15 flats down. This seems way off; typically these
settings would have caused the front carb to be way too lean and the
rear to be rich.
Any thoughts on this? I've not encountered such different settings
before. Also, the erratic idle rpm seems to come and go now, so it's
not fixed entirely. Could this be a float bowl problem?
Thanks in advance for any thoughts on this.
Jeff
Jeff Boatright __o_\__ '65 Austin-Healey Sprite
http://userwww.service.emory.edu/~jboatri/sprite/sprite.html
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