take #1 spark plug out...gently place a long screw driver into hole(gently) and make sure its straight...to prevent screw driver from binding up on piston and creating damage
then rotate crank til number 1 is all the way up...if your not on compression stroke then notches on cam gears will be pointing down
watch screw driver very close. once your close to TDC. while rotating slowly the screwdriver doesnt move for a slow turn then stop...your at TDC
or what i always do. watch screw driver and once it begins to go back down then i reverse the crank and little bit to where TDC is
once you have it on correct stroke and piston up then check your markings
over the years the dampner(crank pulley) dry rots and the rubber becomes weak
its possible for the pulley grooves to rotate
then rotate crank til number 1 is all the way up...if your not on compression stroke then notches on cam gears will be pointing down
watch screw driver very close. once your close to TDC. while rotating slowly the screwdriver doesnt move for a slow turn then stop...your at TDC
or what i always do. watch screw driver and once it begins to go back down then i reverse the crank and little bit to where TDC is
once you have it on correct stroke and piston up then check your markings
over the years the dampner(crank pulley) dry rots and the rubber becomes weak
its possible for the pulley grooves to rotate