With the choke "on" the butterfly or throttle must be .025" open which is
measured between the throttle body and the butterfly. To open the clearance
bend the choke connecting rod smaller or put more bend in it. If the opening
is too big straighten the rod. My car ran like crap with the choke on and
when I adjusted it to spec it ran a lot better.
With choke "off" the idle screw on the carb is used. The more the butterfly
is opened the faster it revs, natch.
Hope this helps.
----- Original Message -----
From: "John Schmitt" <email@example.com>
To: "datsunmike" <firstname.lastname@example.org>
Sent: Monday, February 12, 2001 2:43 PM
Subject: Re: SU needles
> Thanks. That could be it. tell me what I am to look for with choak full
> John Schmitt Telecommuter External # - 847-458-7829
> pager 800-759-8888 pin# 8710561
> "datsunmike" <email@example.com> on 02/12/2001 11:48:57 AM
> To: John Schmitt/Schaumburg/Contr/AT&T/IJV@IBMUS
> cc: "Datsun Roadster List" <firstname.lastname@example.org>
> Subject: Re: SU needles
> I just ordered a set of pre-smog needles for the 2L carbs. After examining
> all the needles I have I noticed the smog needles were the richest
> especially at WOT. They are tapered much more than others I have.
> Your rich burn at idle could be due to several factors however such as too
> much choke or incorrect choke setting of the butterfly or pooling of gas.
> only use full choke upon startup and then immediately give less choke
> it is warming up and while driving I use only enough choke to give me a
> "clean" pull when accelerating.
> After measuring all the SUs I have I noticed all were incorrectly set re:
> opening of the butterfly on choke. I had to bend all the choke rods to get
> the correct opening.
> ----- Original Message -----
> From: "John Schmitt" <email@example.com>
> To: <firstname.lastname@example.org>
> Sent: Monday, February 12, 2001 10:09 AM
> Subject: SU needles
> > I have a 69 2L with a presmog distributor W/O smog pump. I run it at 16
> > deg BTDC and get pretty good performance. I am on an engine rebuild of
> > about 3000 miles ago and have not really abused it.
> > I say all of that because I have always gotten a black smoke at startup
> > have a pretty acrid exhaust smell. I am told that it is probably due to
> > over rich condition because that is the way they set everything in 69
> > accounting for a smog pump recycling those emissions.
> > I have read, in this forum, several time that folks were experimenting
> > different needles to cure this rich running. I have never seen any
> > response that the magical cure has been found. Was the US the only area
> > have received the SUs without a smog pump? I doubt that Australia
> > required it in 69 but they all got solexes. What about Canada? Someone
> > surely got the SU - 2000 that did not have a smog pump and had proper
> > needles.
> > Thanks to any replies in advance.
> > John Schmitt Telecommuter External # - 847-458-7829
> > pager 800-759-8888 pin# 8710561