ok my 1985 150 prospector just strarted to get a know from under the valve cover i think its lifter but not sure and also is it safe to run with the knock

 

get a knock not know

 

knock could mean lots of things, anything from bad gas to a motor starting to go very possible the timing is out. i wouldn't just assume its a lifter myself. if you have some tools and skills i would start by checking the plugs and wires otherwise it's definitley time to see a mechanic and have him figure out the problem, driving it short term will probably not hurt it much if it's one of the things i am thinking it is but long term could hurt it bad so have it checked soon on another note have you checked the oil recently?

 

yes it was good i think i found out its coming from the flywheel