thats the flux capacitor
its the auto choke, sounds like its started to work
when the engine is warm check that both the water hoses going into it are hot, if so may as well try and make it work
look where the hoses go itno a round chamber, one one chamber is a litte bolt / screw thing, remove the zipti and with the enging cold adjsut it till the choke flap on top the engine is jsut closed, idle should be higher until the engine wamrs up then drop back to normal
if it doesnt drop you might need to adjsut the fast idle (read the manual) or if the flap never opens again once warm youll just have to adjsut the choke off, basically with engine cold turn the screw till the flap is open
migth take a few goes to get right but worth it is it all works