First Friction bike problems. need help!!

Hello i have built my first friction drive motorized bicycle with an old mountain bike and a homelite super 2 31 cc motor. my main issues are with my gas tank, my engine mounting system and with stopping the motor.

my first problem i assume can be fixed easily but i dont know how. my gas tank has a hole in the top so air can enter the tank so a vacuum isnt made. my issue with this is that when im riding i loose alot of fuel. i was wondering what i could do to prevent this.

my second problem is with my mount. it is very stable and works great but when the engine starts it vibrates so much that the screws holding it on the mount (these screws screw into the engine block) fall out. i tried using locktite blue but it still didnt work. should i use a stronger locktite?

also i need a good idea for a kill swich.

thank you for reading this and please help!
-NOHENNS

Thank i need to try the smooth tire trick... i switched to red locktight and lock washers but because the screws screw into the engine block i believe that they heat messes with the lockticht

thanks again
-NOHENNS

ps my bike works now i just get tired of tightening the bolts after every