datsun-roadsters
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RE: ADQ needles

To: "Pam & Paul Bauman" <plhbauman@earthlink.net>
Subject: RE: ADQ needles
From: "Brian Hollands" <bholland@hayes.ds.adp.com>
Date: Mon, 11 Jun 2001 11:17:47 -0400
If you can't get it to idle below 1500 rpm, that sounds like a vacuum leak -
have you put a vacuum gauge on it?  I'm assuming your initial spark advance
is set correctly.
Mike's right, check your idle mixture and your float level as well.  Also,
make sure that neither choke is stuck open.  I used to get one choke to
stick part way on all the time.
One other concern that a lot of folks don't think about.  Carburetors that
have had throttle shafts rebushed due to a vacuum leak at the shaft
occasionally suffer from a more severe problem.  Unknowing owners have tried
to correct the high idle speed by backing the idle speed screws all the way
off - not realizing that that won't fix the problem.  That causes the
throttle butterfly to stop directly against the carburetor throat.
Eventually the throttle plate will wear a channel into the carb body where
the two are in contact.  If that happens, you can not get a proper idle as
the amount the throttle plate is open is no longer consistent around it's
diameter so it won't meter air properly.  This is also why it's important to
put the throttle plate into the shaft correctly - the sharper edge facing
away from the carb body.  A carb with this problem will work fine above idle
speed but won't idle right.  It's difficult to tell if you've got this
problem with the carbs on the manifold unless you've got very long fingers.
If your carbs were rebuilt/rebushed by anybody REPUTABLE, they would have
noticed this problem when the carbs were apart.
Brian

-----Original Message-----
 I still can't get her to idle at less than 1500RPM without bouncing around,
but the mid and high end power is there, perhaps even a little smoother than
before.

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