1988 yamaha blaster 200

2 strokes have no cam, as far as checking the crank thouhg. if you can pull the head off first. then pull the cylinder off and move the crank by hand useing the connecting rod. look and see how bad the skirt is. i would accually pull the case apart and clean the crank area then reassemble the bottom end useing new seals and gaskets. if you are able to do this process, i would recommend buying all the seals and gaskets first. if you wish to purchase a bolt kit to i would do that also before you start tearing the bottom end apart. oh yea get a manual or download one also, it will help