Q-Jet adustment issues, jets?

[dukcaln]

Ok all, I got the vacuum hooked up to the truck, turned the jets all the way in the 1.5 turns out. Was at about 14 on the vacuum. Started turning out the jets and got to about 16 and kepts going. The right side jet came out, so the engine stumbled. Put it back in and went in until vacuum dropped which was about all the way closed then adjust out again. Decided to try left side, turned jet out until I was at 15 on vacuum. Now here is the kicker, I could not get the truck to stumble until the jets were just about closed and then again I could not get the truck to stumble until the jets came all the way out.... so my question is this, why can't I get the jets to come all the way out before I see and stumble in motor. There has to be something wrong? I replaced the filter and gasket, replaced all the vacuum lines... truck seems to runn pretty good. Timing set at 12-14. So what I ended up doing was giving it full throttle by hand and letting it off fast, motor would stumble then recover to idle, I figured it needed more fuel so I adjusted the jets out a 1/4 turn each until i could give full throttle and let off with out the motor stumbling and recovering to idle very quick and smooth.....

So why is it i can turn the jets all the way closed and get a stumble or engine about to die but I can take the jets all the way out with no rpm change untiol they fall out and motor dies..... shouldn't there be a point when the motor stumbles before the jets back all the way out? Sorry to ramble but I am frustrated