What size is a 1979 Suzuki gs750se front sprocket transmission nut

22 in lbs on the small, and 60 ft. lbs on the larger axle nut.

GSX 600F Katana 1989-1991
GSX 600F Katana 1989-1991
OEM Gear Ratio - 14T Front Sprocket / 46T Rear Sprocket OEM Chain - 530 Pitch / 112 Links

Well, the oldest manual I have handy is for a '94, it specs:

Front sprocket nut 84 ft lbs
rear sprocket nuts 43.5 ft lbs
axle nut 72.7 ft lbs

Older manuals spec 67.5 for rear sprocket nut, this was changed to 43.5 due to the large number of problems with stripping nuts/bolts.

Check here to see if your bike is listed, that may help:
http://www.carlsalter.com/motorcycle-manuals.asp

Front sprocket NT 12
Rear sprocket NT 39
Go for 520 O-ring chain 120 links.
D.I.D. or Regina chains will have you covered (retailer's will have bike model charts), or some more trick MX kits are available from m'cycle accessories stores. Cheers.

The stock rear sprocket is 41 tooth. The stock front sprocket is 15 tooth. The stock chain is 630 x 96. You can get OEM parts at www.babbittsonline.com/parts/viewbybrand/parts.aspx

Rear sprocket is $52.91. front sprocket is $21.74 and chain is $201.07
Please rate my answer. Thanks.

The clutch hub nut, the large nut holding the inner and outer clutch hubs on, torques to 110-150 foot pounds. The mainshaft nut that holds the front final drive chain sprocket on torques to 35-65 foot pounds. Engine sprocket nut torques to 150-165 foot pounds. Use two lines of Loctite 271 (high strength, red) on the sprocket shaft. The six small 1/4" nuts that go on the outside of the clutch have no torque specs. The manual says to "tighten nuts until releasing disc bottoms on spacers". Torque them like you would any other 1/4" nut, about 10-14 foot pounds. They should be nylock or self locking type nuts. If not, you can use a drop of Loctite 242 (medium strength,blue) on each threaded stud.

sounds unusual,i havent come across a gsx600f yet,but i do know that some models of earlier bikes,(not necessarily suzuki)use a left hand thread on the sprocket nut,so instead of trying to loosen the nut to the left(as one normally would) try going to the right (as if to tighten it),and if it is as i suspect ,it should come undone...hope this helps

check your oil. check to see if your front sprocket nut came loose, or anything else on that side.

put a 2x4 or similar through the back wheel on top of swing-arm: this will lock wheel from rotating while you crack the nut. 
NEVER put the transmission in gear. 
When re-torquing the nut after refitting, put the 2 x 4 under the swing-arm instead of on top (since wheel will want to rotate opposite direction