Ryan,
I can think of three "standard"items that could cause "new" carbs to run
rich.
First is jetting - The metering needles should be type TZ - lean, BC -
standard, or RD - rich. They are faintly marked on the surface which is
inside of the piston & must be removed to check. Make sure that the
needles are seated with their shoulders or lower edge of the groove
flush with the piston surface. If they were set deeper (too high) it
could cause the carbs to run somewhat rich. The needle jets should be
exactly .100" internal diameter. With the jet adjusting nuts set fully
up the top of the jets should be even with the jet bridge or a little
higher. This is a check, the actual setting will probably be with the
nut somewhere between one & three turns down, (open) from the flush setting.
Second is float level or of course leaking float valves. There are
several different types of needle/float combinations on the HS6. On the
type with brass float, curved float arms, & steel spring loaded needle,
the adjustment should be 5/16" between the curved part of the arms & the
chamber top.
On the type with Delrin spring loaded needle & plastic float, 1/8"
clearance between float & lid.
On the later type with non adjustable float, 1/8 to 3/16" clearance
between the closest part of the float top & lid.
In all cases the measurment is with the spring plunger in the needle not
compressed.
Third is the choke starting enrichment linkage may not be properly
returning the jet to its upper, closed, position. With the choke
completely off, check that the jet raise/lower mechanism allows the jet
to be firmly against it's upper position.
There may be other possibilities but this should be a start.
Dave Russell
Big Sixer wrote:
> Got my BJ7 on the road for an extended drive. Rebuilt engine, NOS distributor,
> New HS6's from Australia.
>
> Engine runs with power, but exhaust is extremely rich. Spark plugs are
> covered with black soot, and the rear tail pipe has black soot.
>
> Car ran fine, but was very hard to start after I parked it for a few minutes.
> Only good thing is that the engine doesn't run on after turning it off.
>
> Spark gap is fine. Valves are a bit loose, but generally fine. Ignition Timing
> is by hand but fine.
>
> Carbs are same setting as delivered by factory. Is this right? Should they be
> leaned out? Is that hard to do?
>
> Is there something I'm overlooking?
>
> Ryan
> 64BJ7
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