Two part question.

[nutz4spd]

I've been working on my GS for a while now. I have replaced the fork seals and fluid. Added in the 191mL per the factory manual. Replaced the rear shocks with Progressive's and OE springs. Pulled the carbs off and cleaned them up and reset the floats (twice now). Since I've never rode one of these new or anything I have a concern about the ride quality. The front is very springy/bouncy. At first I thought the front tire needed to be re-balanced so I did that and it's still bouncy. Is this normal for these older bikes? I figured the front would be a little more solid/stiff.

Also, I've reset the floats to the specs in the manual (22.4mm which is .882 in.) twice now but there is still a hesitation/stumble when accelerating. I've noticed the fuel mileage is also really bad. Any ideas or suggestions on what is needed to make the stumble go away? I'm about ready to just take it to a shop and have them work on it. I prefer not to though.

[Rich82GS750TZ]

Lots of guys change their fork springs to Sonics. See member RichDesmond for sizing and other recommendations.

Are you running with the stock airbox/filter or pods? If pods, what kind? Stock exhaust?

[xkaes]

Two easy, inexpensive approaches that I use:

#1: Use a stiffer fork oil. Your choice of oil.
#2: Add 25mm(?) metal washers (same diameter as the spring) between the tube top bolt and the spring. Your choice of number of washers.

[zuluwiz]

The 850s use air in the forks. Did you include that?

[nutz4spd]

Lots of guys change their fork springs to Sonics. See member RichDesmond for sizing and other recommendations.

Are you running with the stock airbox/filter or pods? If pods, what kind? Stock exhaust?

The bike is completely stock. For now...

[nutz4spd]

The 850s use air in the forks. Did you include that?

I did. the factory spec called for about 7psi. There should be between 7-10 psi in each leg.

[Gorminrider]

Not a suspension guy but things I would try before admitting I had to buy new springs :
-did you measure the springs against the manuals specs?
-you could double-check the oil level in the stanchions..better than adding a "certain amount" I think. Some manuals give the level measurement. You can increase it a little to reduce the airspace ...ie: air-pressure caused by collapsing the stanchion increases the air pressure sooner.

as per xkaes, Pre-compressing the springs with a spacer is common. I think it duplicates the effect of more weight on the front end so maybe you could strap a bag of rocks up there and see if it helps because it can be hard to push spacer in against the spring! It also reduces travel of the stanchion so new springs are better for an all-round stiffer ride. The oil specs might need adjusting with non-oem springs?

Thicker oil would seem to slow the damping...By the way, forks and shocks "heat up" so suspension oil can be affected, depending on what it is. Some Suzukis are very specific wanting some multigrade mixed in there..

[zed1015]

Also, I've reset the floats to the specs in the manual (22.4mm which is .882 in.) twice now but there is still a hesitation/stumble when accelerating. I've noticed the fuel mileage is also really bad. Any ideas or suggestions on what is needed to make the stumble go away? I'm about ready to just take it to a shop and have them work on it. I prefer not to though.

The stumble coupled with the low MPG shows you are certainly running rich.
If everything else is stock the culprit is quite possibly leaking choke plungers which is becoming an ever increasing problem due to their age and the use of ethanol fuels which degrades the rubber seats.
If you cannot find replacement plungers i offer a service to fit new ethanol resistant Viton seats to your original plungers.