You can check the timing somewhat by the checking the valve lash procedure just to see if everything lines up close. Other than that you would have to pull engine side covers off to check for sure.
You could have a in efficient fuel pump or clogged up jets, and theres so much more to check.
05 750,Stock Engine,Muzzy Pro Exhaust, Uni Air Filter,
14" Vision Bruiser wheels, 26" Kenda Bear Claw HTR,
3" PVC Intake w/restriction - 2" ABS CVT, center snorkels,Carbs Keihin-#40 pilots 2 1/2 turns out A/F ,#158/#158 mains w/30 thous. washers under stock NFKL needles, 2012 front suspension,
Mr. Gasket 42s Fuel Pump Mod
10" Hayden s-type Electric Rad Fan Mod - mod fan mount
Aftermarket ebay radiator