no broken spring your lsn is ritch if it bogs but check the clutch by spinning the wheels if it spins nice you are ok if it drags you might have to shim or the clutch spring like yack pointed out but your car would still run it would just want to go out and as for the idle screw when you adjust your idle screw make shure the air filter is off so you can se how far open it is when you brake adjust it so you have about 1 mil gap give or take a little my tz is about 1 mil my mach .15re is about 2 mills all the idle screw is a needle that sets a stop for the carb slider you have to go to break to se where you set the screw i think your idle might be to high and lsn to ritch the trickey thing is when you are to leen the motor races at idle so it can be tricky i sugest you go back to factory settings get your idle screw to 1 mill and if you need more idle adjust it just a pinch you want to idle as low as you can without stalling when you break but i do sugest you buy a clutch some clutch berrings and mby a flywheel collet and clutch nut to have in your box they will break or wear out i use mip clutches and they last a long time