In 5th gear when i have my 05 gsxr-750 at full throttle the bike seems to cut out at around 105 mph. could this be a fuel problem?

SOURCE: No power and high fuel consumption

Suspect worn needle valve & seat assembly !---Quick test , with care>Whilst riding on open road &holding throttle at set position, switch off fuel supply & note IF engine speeds up, IMMEDIATELY Back off throttle, watch rear vision mirrors for traffic behind & switch on fuel supply!---If that small test indicates Carburettor area of further examination, UNLESS YOU ARE QUALIFIED the needle valves need to be examined byTrained eye!-(Especially wear on sides of needle valve & ALSO, check "floats"Stay Upright Des

SOURCE: Havin problem with 5th gear (OD) Bike slows down

Sounds like the clutch might be going bad.

SOURCE: cutting out at higher rpm

If the engine is the DOHC 16 valve engine inline 4, and has multiple carbs, then I have 2 suggestions for you, First thing I would take the carbs off, as a whole rail, and have them ultra-sonically cleaned at a shop, and the diaphragms checked in the tops. After that, you need to have the carbs synced while on the bike. I have a GSF600S and it was basically opposite your problem, it had a sputter in the low rpm range, and the carb syncing fixed it, and they honestly weren't that far off. The way those carbs feed fuel, if one is giving too much fuel then it will cause ur plugs to foul, or flood that cylinder, causing the issue. For the carb syncing I suggest building this tool, which I did for my bike.
http://www.powerchutes.com/manometer.asp
It's a liquid column differential manometer, which very accurately and sensitively measures the vaccum on the different cylinders of the engine. The only other thing I can think of is your ECM, which controls the engine, and incorporates your rev limiter. These are pretty pricey, so I would do the steps above first.

SOURCE: 2002 gsxr 600 cuts out full throttle

if this bike is carbureted i would say your main jets are plugged.

SOURCE: 1991 GSXR 750 cutting on low revs

run a can of Seaforam in the tank..purchase from Autozone put in 1/3 to two gallons gas drive it around for at least 10 miles to insure it cleans out the whole carb system.if that doesnt work, check all carb hose fittings when bike is at idle spray some Chemtool B-12 ( also at Autozone) around the carb hoses and manifolds..if idle increses thats your problem. Caution: chemtool is very toxic wear gloves and a mask.