Hesitation on accelerating - 1800

Hello good people

Got a small problem with the kombi - its an 1800, twin solex carbs, single vac dissy with elec ignition...

Seems to hesitate when accelerating, but only in the 'middle' third of the pedal travel - the first bit is smooth, and there's plenty of power in the end, just the bit in between seems lacking which makes normal cruising/ gentle acceleration a bit of a chore.

Valves are checked, timing is spot on (with strobe), carbs have been balanced and mixture re-set (by vw garage), but still got the damn hesitation.

The only thing i noticed was the timing mark (although dead consistent - no jumping), seemed to 'stick' on about 10deg as the revs are increased, and then suddenly jumps to about 20deg before continuing on as expected. Could this be the prob?

I took the dissy apart, vac unit seems to function well with no leaks, checked the shaft and the weights in the bottom and all is free and good... one of the springs seems slightly looser than the other but this looks normal to me (cant see any wear)

Am i barking up the right tree????

Any help appreciated, Sam 😉

Seems like a bloody good place to start.

Any chance of borrowing another one - just to see?

Been through similar problems with our 1800. The baseplate in the distibutor was worn. It would be worth trying another distributor if you can.

maybe fuel pump on the carby's?

/ carb diaphragms?

nick

carb diaphragms = the accelerator pump ones yeah? Will check those 😉

So my timing mark 'jumping' about 10 degrees is def not right, yeah?

Is the baseplate of the dissy the one with the weights on or the one with the points etc on? How does wear here affect the advance mech?

(sorry, i like to understand whats going on - anal family trait i know!)

Will try and look for another dissy and try that

Sam