I'm working on 1990 GPX750. It was kept outside in three years covered by a blue sheet. After I crean its carburetor, it starts and run good but the engine sometimes stop when it's idle. Then it starts right after. The engine doesn't stop very often but it happens when the engine is warmed up.
I checked wiring if there are any corrosion. The TIP sensor on the fuel tank seems working okay.

Please give me any advice if anyone know the idea where I should check for this kind of problem.

Thank you.