Bill says:
"When I am trying to tune the carburetors I get a backfire out of both
carburetor throats when I rise the RPMs. It happens almost
immediately. With the backfire I get a white smoke/mist out of the
carburetor throats which I think is a fine mist of gas. These are the
problems I think that could cause this problem.
1. Leaky needle valves.
2. Fuel pump has to high pressure (I will measure this
tonight, what is the correct range)
3. Incorrect float levels (to high)
I am leaning towards number 2 since it is both carburetors."
I thought that fuel pressure from the carbs into the engine was governed by
the floats, and that an overactive pump would be unable to transmit surplus
fuel directly into the manifold. So perhaps old needles and seats are your
answer. With the engine off and the ignition on, does the pump keep
clicking, or does it fill up the floats and then stop?
When I had a similar problem with my '74, I was told that a cloud of gas
spewing backwards out of the carbs was a sign of extremely poor compression,
or timing way out of whack. Sure enough, in my case it was the compression,
as I had forgotten to tighten the new set of sparkplugs that I had just
installed. (duh.)
Regards,
Charles
'74 Midget
'72 Midget
'68 Sprite
Bloomfield, NJ
cdsorkin@cdsorkin.com
"How about we duck inside for a Hen?"
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