In reply to a message from bobsxk120 sent Mon 24 Aug 2015:
Bob,
If the fuel is coming out of the float chamber overflow
then it is usually either a sticking float needle valve
or a sunk float - if it is only coming out of the jet in
the carb throat then it a float level issue.
The float chamber valves can stick open for a only a
couple of reasons:
- Dirt/Swarf in the seat.
- The seat not seating/sealing in the lid.
- Bore in the seat badly worn (only seen this once).
- Damaged tip on needle.
- Needle upside down.
- Lever binding on pin or arms of float bowl.
If you replaced the seat and needle, kept everything clean,
and adjusted the float level correctly, then it is usually
either #1 or #6.
Your chamber may have ‘‘Wobbly Float Syndrome’’. Take the top
off and have a good look at the lever arm. adjust the legs
so that they have a minimum of play side to side against
the protruding arms on the lid AND the pin. They should be
free but not sloppy.
If the carbs have sat for a very long time the floats
sometimes bind on the rod due to rust and/or varnish. I
presume you would have noticed this while rebuilding them.
If there was any Silicone or other sealer visible on the
carbs when you started then you may have a bit of silicone
somewhere in a passage.
The last 140 I did had been ‘‘repaired’’ with silicone. In
the end I had to completely strip the carbs and blow out
all the passages (not to mention replace various screws,
seals and springs which were either wrong or missing).
If anyone knows Bubba, please take his silicone cartridge
away and explain that silicone does NOT belong on carbs,
that the jet tube seals are important even if you can seal
the bottom cap with silicone, and that the spring on the
hisser needle is indeed important. I tire of finding
Bubba’s ‘‘repairs’’.
Andrew–
The original message included these comments:
It seems that the front still likes to overflow and causes
the engine to die out, too much fuel!
–
1968 3.8S
Zurich, Switzerland
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