White smoke in the exhaust usually indicates water, e.g. from a blown head
gasket, which could cause a misfire as well. With the misfire is the tach
steady or flicking about all over the place? If the latter then that
indicates an ignition LT problem i.e. connections, points etc. If it's
steady then it could be HT or fuel. A knackered timing light and not
getting the problem on the driveway complicates things for further
diagnosis. If it only happens under load then it could still either be HT
or fuel, as the higher compression pressures under load make it more
difficult for the spark to jump the gap as well as needing more fuel. As a
first step I'd check the fuel delivery, with a pipe removed from a carb and
directed into a container it should deliver *at least* one Imperial pint per
minute with negligible bubbles. If that's OK, could still be carbs - if HS
SUs - but it sounds like you have a single Zenith. You really need to get a
timing light (inductive pickup type) and try and rig it so you can see the
flashes in the cabin whilst driving. If the flashes remain regular on both
coil lead and plug leads when the misfire happens then it is probably plugs
or fuel. If the flashes get irregular on the plug leads but are steady on
the coil lead it is cap or rotor. If they get irregular on the coil lead as
well it is coil or ignition trigger.
PaulH.
----- Original Message -----
> ... I took it for a test drive this weekend and it seemed to be good up
> to 3500 then it started sputtering and acting like the timing is off...
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