Just getting this 83 put back together. The carbs were off, cleaned, 1 new diaphram and slide. All carbs look good. The sync looks good although vacuum seems a little low
(29-30hg). Idles great, starts great. When I take it up to 4500-5000 rpm (in driveway, not on road) it starts to miss fire. It appears to be on the 3-4 cylinder side. Any ideas?