I have a two group VFA Espress lever machine. I bought it a while back and just got it hooked up recently.
I'm not sure why but when I pull the lever down to pull a shot it doesn't seem to "gulp" very much water. I also have an Cimballi M-20 which I have been using for several years. When I release the lever it returns almost to the top before it starts to come to pressure and start pulling the shot. It takes about three pull to barely get a 2 ounce shot. I leave the lever down for a long enough time for pre-infusion so it has time to "gulp" more water but it doesn't seem to get much.
Any ideas?
Thanks

One other thing. If I pull the lever down without coffee in the portafilter water comes streaming out normally as it should, so it;s no a blockage.

I have a hard time coming up with useful specs on that model, do you know the cylinder size? Diameter & Length. That way you can calculate the potential maximum water that could fill. Of course air will be trapped as well, depending on the piston design.

One thing you can try other than calculations is the Fellini move:
https://www.youtube.com/watch?v=LRScmTLim9w

Basically it gets more water into the cylinder by pumping the lever a bit to force some water into the puck at a bit of a higher preinfusion pressure. It may also work to get rid of some of the air in the cylinder, again depending on your machine design. It's worth a shot anyway!

How many grams are you dosing and into what size of basket? More headspace above the puck increases the volume of available water.

On my Astoria, I can dose as low as 12 grams in a basket that maxes out at 16.5 grams before I get puck soup and a not very pleasant espresso. When dosed at 16.5 grams the shots are lower volume, although not as low as the .7 ounces you are getting.

You might want to show a picture of the group itself to help us identify any possible mechanical issues. VFA levers appear to be very rare, I wasn't able to find a picture or diagram of one.

I dose about 14 grams the same as my Cimbali M20 but sometimes a bit more in a triple basket. The lever goes up about 80% of the way before it comes to pressure. The whole machine looks in close to perfect condition and I don't think it's been used much. Both of the levers act exactly the same. I'll try the multi pulls to see if it fills up more but having used a few commercial spring leaver machines it seem a bit odd.
I'll try to post a photo later.
Thanks again

One more

That's a nice looking lever. The groups look very much like Faema, which isn't surprising. I would be interested to know if the groups are fed by an HX.

As to your problem, did you change the piston seals before you started using it? The excessive travel before engaging combined with low volume could be steam and water escaping into the area above the piston. Did much water leak out of the group when you first warmed it up?

Well it's not a dipper and has two copper lines feeding the group. I am going to look at it again today. From the diagrams I have seen i would think that when the piston is raised it would open up the passages and allow the chamber to be filled with water, not just a sip but a gulp. Didn't replace the seals but they seem fine.. no seepage at all.

Those appear to be a version of the Faema Zodiac group, which means you probably still have parts availability. (VFA is out of business.)

As a simple test of the piston seals I would try pulling a shot with a blind basket. The lever should rise to a resistance point and stop. If it slowly continues past that point either the portafilter gasket is leaking or the piston gasket is. (As a safety precaution, drape a towel over the front of the machine and lower the lever to its detent before removing the portafilter. Hot water smarts when it sprays you.) After the machine has cooled, pull the piston to check for water above the piston. If there is rust on the spring it is indicative of past and possibly current leaks.

I don't think it is a flow issue, but the easy test would be to preinfuse for a couple minutes on a test shot. If the volume is the same then flow isn't the problem. (Grind fine enough that no drops appear while it is still preinfusing.)

I fired the machine up to try things again. The length of perfusion didn't seem to change things but I did notice one thing. The Feline move didn't change things. When the machine is not pulling a shot the lever is back past centre, not vertical. Kind of at an 11 o'clock position. I pulled a few shots letting the lever go all the way back and found that with two pulls It would do a bit more than two ounces of coffee so it's not as bad as I thought. My Cimbali needs a pull and a half for a full shot so maybe two pulls isn't bad. any opinions on this?
I have a few Photos of the group and would like to confirm it's make if possible so I can get seals as needed.
Thanks for the help so far.