Check the side stand switch I had exact same problem . It just needed a tiny spring inside stretched to make a better contact..
You may also look at your clutch switch as well just in case .
Have a look at the injector relay too .
Make sure you don't have a kink in the fuel line that can do it too.
Have you cleaned your air filter lately.
Also check your petrol tank breather isn't blocked .
Hope you cure it .