ok i shortend this up for all yall. i ended up with this older LT 80 from a afriend of a friend with a a chunk missing out of the exhuast manifold so it was pretty much running with no exhuast. i wanted to TIG weld it but i couldent get in there without taking the engine out so i just put it back together withJB weld. it held for a while but then it just came back off. so i have been driving it around with pretty much no exhuast pipe. but i noticed the carb bolts were loose so i put loc washers on them and put them back on and then the next day after riding it, the bike started cutting out. and i look down and the idle screw was missing from the right hand side of the carb,

So i have 2 questions would the missing screw cuase the bike to cut out and what is the best way to fix the manifold short of taking the engine out.
thanks

 

bump come on i need some answers this forum has never let me down like this before

 

Yes the screw missing will cause problems.It'll suck air. The loose carb may have also sucked in the o-ring.

Just remove the cylinder from the machine and weld the broke piece.