How much fork oil in the tuono 2007 1000r usd showa forks please

If I have found the right vivavity model, then yes.
they regularly get rusy, need freeing, and refilling with oil.
See here.
http://www.scooternations.com/showthread.php?195-Freeing-USD-%28Up-Side-Down%29-forks

you need fork oil

Having removed the forks, you will need to undo the lower damper bolt first, this is located on the recess inside the fork where. The spindle goes through, this will then alow you to remove the oil from the fork, and the leg will then be free from the stancion moving freely down, if the fork doesnot come apart, you will have to remove the retaining clip from the seal and pull the fork apart sliding the fork leg up the stancion and sharply pulling down on it to pull the seal out, repeat this till theseal comes out, (tip) undo the fork top nut while the forks are still fitted to the bike.

It's hard to get specs in mls or cc these days so I'll let you in on a BIG secret(don't tell everyone,hush hush,& we stay wiser than others,promse not to tell, cross your heart).

Ok here we go- NO this ISN'T a joke so listen carefully.

Set the oil levels in the front forks

with the cartridges blead(simply draw up & down on the damper rod & you can feel the air bleeding out),

& before you re-fit the springs,

With the forks fully compressed
,
The fork oil level should be 100-110mm from the top.
This applies to basically all forks(except-a few like MX showa on certain RMs' & the new kawasaki 250 MXer.)
Hope this helps
Regards Andrew

Outer cartridge on the twin chamber Showa fork for an RM250 uses 350ml of 5W oil.

the offset screws are air bleed screws.. the top are compression screws and the bottem are rebound.. the top ones should be set to around 10 out from all the way in and the bottem at 12 from all the way in

What weight oil? 10w or 15w is good for fork oil. Also check that your valve that controls the oil passing back and forth is not obstructed inside the fork tube.

set your compression out 10 or 11 your rebound 9 or 10 and your fork oil height to roughtly 380cc.since its in 03 u should drain the fork oil out, u have to unscrew the top cap of the fork while its in the triple clamps( because its easier this way), loosen then take the fork out of the clamps, unscrew the top caps and pull the fork tube down and turn the fork upside down to drain the oil out then hang the forks up upside down for about 15 minutes then add the new oil right in the fork tube were you'll see a spring, just add the oil in there and you'll be fine and u should replace it with a good medium weight oil