Newbie again let me clear the question up a little . 2001 yz426f bought it from a friend they say he walked the hound out of it. i got it home tried to start it did not start so i checked the oil it was milkey so i draind all the oil flushed it out real good let it set for a few days to let it drain real good. replaced the oil with new oil . the bike started fine cut it off checked the oil it was milkey again . replaced the water pump seal problem solved. flushed all the milkey oil out again put new oil in started fine let it run for a minute or two cut it off tried to start it back it sounds like the piston is scrubbing while moving up or down . moved it with a ratchet back and forth feels pretty good . so we tried to kick start it and it gets stuck. can free up with socket wrench fine just that one point it gets real stiff and wants to lock up. when i started it it ran fine dont under stand.