yerr if you pull the clutch in the kickstart doesnt engage so you definatly had it too tight
do the revs go up a bit when you lose power? like you are accelerating but then it stops speeding up but the revs still go up a bit..
if so your clutch is slipping costing you power
however i dont think the clutch is the issue, can you get hold of a compression tester?
you can buy them brand new for about £15 - £20
you screw it in the spark plug hole tight
connect the pipe leading to the gauge
press starter button until the gauge peaks and doesnt go any higher
you need to have the throttle wide open and have a warm engine to have a accurate reading