Just wondering if anyone else has had this trouble, bike use to start fine then run for a while then die out so I took the spark plug out and went to kick it over to check for spark but it still had full compression even with the spark plug out.
when you turn the motor over you still have to turn the camshaft which means you still have to compress the cam springs which feels like compression. Did you use a gauge ? Those motors have an automatic decomp which dumps one exhaust valve when starting.
Yeah, this sounds like something is creating drag in the motor. These four strokes have a number of components that can cause what you described. I wouldn't attempt to start it any more, instead the motor needs to pulled and disassembled. If something has been creating drag there may be signs of metal shavings in the oil filter but even if there isn't I'd tear the motor down anyways. For me, theres few things that ruin a great day of riding as much as a shitty running bike. I hope whatever it is you find is simple and inexpensive. Let us know what you find, If you're up to it, pictures make for a great post too.
