Hi David,
The stumbling under acceleration could be as simple as the dashpots not
working correctly or they don't have the right grade/quantity of oil in
them. A slight possibility is air leaks in the carb or manifold
mountings. Backfire through the carbs would indicate a lean mixture or
retarded timing.
The slack in the advance mechanism, with the distributor at rest, is not
completely unexpected. With the engine/rotor turning even very slow rpm,
the slack will be taken out by the centrifugal weights.
I would check for anything that could cause a lean mixture on
acceleration, especially the dashpots, & set timing to about 36 degrees
at 4500 rpm, vacuum advance disconnected for test. Other checks would
involve having adequate fuel flow clear to & through the float bowls.
If you disconnect the fuel line at the first carb & measure pump output,
it should pump around one pint in 30 seconds. This equates to a flow of
around 14-15 gallons per hour. The flow to the other carbs should be in
the same ballpark or a little less, depending on the plumbing
arrangement. Make sure that float levels are not set too low & that you
have the correct metering needles installed, marked DJ I believe.
Good luck,
Dave Russell
davidwjones wrote:
> Stumbling is worst for some reason under (attempted) acceleration
> in 1st gear. Sometimes accompanied by a backfire through the carbs.
>
> Question: If I manually twist the rotor in the distributor, advancing it, it
> does not exactly "snap" back to the non advanced position. However, to my
> recollection, it never has, in many years of driving..
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