I also have a similar problem on my '59 - the one where the mixture won't
lean out properly.
The PO, or his mechanic, even took out the fast idle screw. With the idle
screws all the way down I'm at about 2000 rpm.
Well,,, the car is, not me really.
On 05/05/99 06:58 PM Sumner Weisman said...
>My newly rebuilt SU carbs were installed a couple of months ago and are
>working nicely. I used the TRF rebuild kits, which were fine. Prior to
>rebuilding, I sent the bodies out to a very popular company for rebushing
>and new shafts. That's where the problem came in, and I'm just passing it
>along for information for others contemplating the same thing.
>When I got them back, they looked great and I started reassembling them.
>When I mounted the throttle stops to the shafts with new tapered pins, I
>noticed that, even with no adjustment screws installed in the throttle
>stops, the butterflies didn't quite close and the stops were bottomed out.
>They were nearly closed, but I could see daylight and I sure didn't want
>them partly open when I was trying to adjust the slow idle speed. My
>conclusion was that the holes in the shafts were drilled slightly at the
>I had two choices. I could have sent them back, but of course I was in a
>hurry. So, I ended up drilling new holes through the shafts and the collars
>of the throttle stops, about 90 degrees from the original holes. The holes
>were drilled at the proper angle so that the butterflies not only closed
>completely, but there was now plenty of adjustment range for the screws
>well. That completely solved the problem, and everything works fine.
>The reason for this note is that I've been wondering if anyone else has had
>this experience. Is there any possibility that there was a variation in the
>angle of the original holes drilled at the factory in the throttle stops? I
>suspect not, and that there was a just slight screw-up at the company that
>installed the shafts. What do you think?