Adjustment Of Dhla Pump Mechanism

[barker_001]

In my ongoing quest to solve the hesitation that is affecting my Lotus Excel, I've noticed that the nut + locknut which set the accelerator pump stroke are in different positions on the two carbs. There looks to be about 2 - 3 turns difference between them, and as far as I know they have never been adjusted. I borrowed a pump tool and the volumes all seem to be even, 7cc +/- 0.5cc.

 

However, I'm wondering whether one pump is starting to operate before the other, and if it might be causing my problem - the engine runs smoothly at a constant 1800 - 2000 rpm, the hesitation only starts when I accelerate.

 

The Des Hamill bible says thou shalt not adjust thy pump strokes, but I've fitted an overhaul kit which included new diaphragms, so surely after this some adjustment may be needed? Should there be any free play between the end of the pump actuator arm, and the brass plunger attached to the diaphragm? Or should it be resting against it under non-accelerating conditions?

 

Thanks for your thoughts...