1985 atc 200s

[250rkyle]

My 1985 atc 200s top end got a little hot and seized the bearing on the end of the cam and turned It a blue
Color. I take it that it isn't getting oil in the top end.Any ideas why?

[kb0nly]

Yep, sounds like you starved for oil. Has anyone been into the motor? The most likely causes are plugged oil galley to the head, sludged up oil filter rotor, low on oil, etc.

I have seen this a couple times now where someone tore down the top end and reassembled and had to much RTV on the rocker cover by the rear cam journal, what happens is a bit of RTV gets loose and gets into the camshaft, the camshaft is hollow and the oil gets pumped up and into the center of the camshaft where it comes out of holes at each bearing and also fills up the square reservoir under the cam so the cam lobes splash through oil as they go around.

Also make sure that little black rubber plug is in the hole on the head by the end of the cam, that diverts the oil to go through the small hole that faces the end of the camshaft. My guess is you got a blockage, i haven't seen an oil pump fail on these yet. Also when you check the oil don't screw the dipstick in, just dip it to the threads on the cap, if you screw it in to check then your oil will always be low.

[250rkyle]

If you screw the dip stick in to check the oil could it be possible
That there wouldn't be enough oil for the pump to take it up in the head?