Stomberg mixture puzzle
Posted: Mon Jul 27, 2020 9:22 pm
A couple of years ago I had the Strombergs on my '72 Sprint rebuilt by Joe Curto to home market/Euro specs, since all of the Federal emissions gear had already been removed by the PO.
That, along with recurving the distributor to Euro specs transformed the car. Very quick, no flat spots. Joyful.
But the plugs were dark. And lots of smoke on acceleration. After about a year, I utilized Joe's needle exchange to go to leaner needles.
I set those at the leanest setting. Car still ran fine. But the plugs are still dark -see pics. And still smokes when accelerating.
So in preparation to call Joe for even leaner needles, I went through the Stromberg mixture setting process.
When I lift the pistons the 1/32" inch (or so), the idle goes from 900 to 1000, then down to 850 or so, very slowly dropping from there.
Which is my understanding of what should happen with a mixture that's slightly lean, not rich.
So if my mixture is lean, why are my plugs black?
Signed,
Confused in Tulsa.
That, along with recurving the distributor to Euro specs transformed the car. Very quick, no flat spots. Joyful.
But the plugs were dark. And lots of smoke on acceleration. After about a year, I utilized Joe's needle exchange to go to leaner needles.
I set those at the leanest setting. Car still ran fine. But the plugs are still dark -see pics. And still smokes when accelerating.
So in preparation to call Joe for even leaner needles, I went through the Stromberg mixture setting process.
When I lift the pistons the 1/32" inch (or so), the idle goes from 900 to 1000, then down to 850 or so, very slowly dropping from there.
Which is my understanding of what should happen with a mixture that's slightly lean, not rich.
So if my mixture is lean, why are my plugs black?
Signed,
Confused in Tulsa.