Dismantled carbs again to find source of wicked missing.
Found that LH carb jet needle was stuck about 5mm higher than its proper position! I had previously examined the slides by removing and replacing while carbs were still bolted to the inlet stubs, but do recall having trouble getting needle to enter jet when replacing slides. Got it very wrong on LH slide!
Re-assembled and re-fitted with new flange O-rings, after checking carb synch. Took bike out for a blat to Sawani – it now runs normally but still has a miss and a cough when accelerating hard in high gears under load.
Next – change plugs, fit K&N-type filters, and see if that makes any difference. Try needle in a different position, then check slide cutaway.
NB on refitting RH carb, noted that ¼ turn on flange nuts meant the difference between “hardly more than finger-tight” and “slide jams up in carb bore”. Slide could stick, and backing off one nut by ¼ turn would result in it going “ker-chunk” back down to the throttle stop again.
