Tim is a reliable source. Some carb designs have shaft seals in the
carb body that can be replaced if worn. Some have replacement throttle
shafts that need split screws, attaching plates to rod, to be removed to
put the throttle plates on the new shafts (my MG and Jag SU carbs), but
new screws are needed, and must be spread to lock. Lower price range
carbs do not allow for changes at this level. If your shaft is worn,
and cannot be replaced, air will enter the shaft into the vacuum area
and disrupt your mixture.
A favorite test is to spray a fluid around carb areas that are suspected
of leaking. Gasoline is NOT recommended. "Starter Spray" in cold areas,
and even WD 40 can do the job. While idling, lightly spray the suspect
area. An increase in rpm means it got sucked in, enriching the
mixture. This is also good for gasket areas of the carb and intake
manifold.
Steve
Ronak, TP (Timothy) wrote:
>Joey,
>If fuel is leaking around the throttle shaft it is likely worn. This may
>make it difficult top obtain a consistent idle as a worn throttle shaft
>usually leaks vacuum. A vacuum leak will result in faster idle when warm due
>to leaning of the air/fuel ratio when idling. It may even whistle (If the
>exhaust is quiet enough to hear it) One way of checking is the use propane
>around the throttle shaft while running to see if the idle changes. Not sure
>how old you are but I would suggest that an adult help out with the propane
>test for obvious reasons.
>The correction is to replace the throttle shaft plate assembly or the entire
>carb.
>
>Best Regards,
>
>Tim Ronak
>
>
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Steve Laifman
Editor
http://www.TigersUnited.com
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