[Roadsters] su carb problem.

[robert k. smith]

 hi keith, im working on a 69 2000, that belongs to a friend.
it idles, ok, and pulls resonably well, from idle to 6k rpm.
the problem is, part throttle cruising at 2.5k--3k rpm.
it sounds like the engine is missing a little, and the throttle
response is kind of flat.   3200-3500 rpm or above, the throttle
responds better, more like MY roadster. fuel press. is 4-4.5 lbs.
ive ckd, and raised the float level 2 mm.,  ckd, cleaned points,
tried another condenser, all no help. point dwell is pretty steady
when reving engine. the timing is: 15 btdc, vac.disc., raising to
about 30 deg. at 2500-2800 rpm.  total mech.adv. is 35-36 deg.
  ive synchonized the carbs at idle, and with throttle. ive got
the mix. set where it idles good, hot. ive messed with su's
for many years, but im stumped on this one.
 if you have any ideas, please call or email me.

      thanks, bob smith, ohio  614 418 9911

 p.s. i changed the cam timing, when i first had this
problem. it was almost 1 cam toothe retarded. i changed
the cam forward 1 toothe, and now it is just a fraction on
the advance side, much closer to being correct, than before.
 the engine seemed  to pull better in the lower rpm range,
but i still have the part throttle problem.