Geeto, they do not have pumps and I'll answer your rhetorical question by flat out telling you the Amals are not nearly as refined as the Miks or Dellortos since they have much fewer selective tuning pieces and the jumps in between those available are much larger than the Dellortos and Miks.
So, this generally means that to tune them to acceptable levels of performance for road going bikes is easier but without modifying selective bits (with a drill or file) it generally is not possible to get as fine as results as possible with much patience and tinkering with off the shelf parts available for the other carbs.
But.... most tuners truly don't ever manage to get a high strung road going engine dialed in perfectly for any given day regardless of how refined a metering device they have hanging...... when is the last time you saw a guy with his log book at the track and all his meteorological equipment on hand?
Does this make sense?
However, if one is a tuner and isn't afraid to work over needles, slides, air bleeds, transition holes, etc...... most excellent results can be had that will rival anything out there and even for a perfectionist type tuner........ these same practices are needed even with the Mik's and Dellortos and are often much more cost/time effective than waiting to try out another bit on the way which may or may not be spot on just what the Dr Ordered.......
the caveat on the phenolic slides......... they suck as they are tremendously light and their surface does indeed seem to create a certain "stickion" to the slide bore
I never run them without a beefier slide spring and the available brass slides are better...... especially if you hard chrome them
The amals are very light, very simple, very compact, when used parallel the enricheners can all be easily linked, and flow very well per given bore area........
and they readily lend themselves to easy "owner hands on" tuning
as evidenced by my very rare and highly modified Mark 1 1/2 concentric (predecessor to the Mark II) fitted on my flatty forward facing with an open velocity stack
want a bag of worms? try tackling something like that, it's almost as much fun as doing blow thru pressurized carbs
I'm sure you've seen pix of it as well as my very long runner'd spread bore induction having forward facing tillotsons?
both work very well and my flatty will cruise 60 and under returning better than 80mpg, returns better than 70 @ 70, and has topped out at over 100 mph...... will cruise 80-85 all day long
up a long way from stock fuel mileage of 30-35 mpg and 60 mph is all she wrote
in any event, I have several many Mark II's
one other carb I'd be tempted to do on a XS would be.......
one of the twin throat CV Mic carbs having the 32 or 34mm bores
always thought a pair of them would be nifty on a CB750
they can also be sourced with smaller bores
I have a small collection of those types too...... they are kinda neat to look at
