trouble with a CRF 80R

[EXrider65]

I have a noise in the top end of this 80r 4 stroke, we just put a new piston and had everything checked before we put it back together. Story is he sunk it in a DEEP mud hole and it locked up but eventually got it running. So then it started to make a noise in the upper end. Question is could it have broken something in the oil pump area and not getting oil to the top end???????????
ANY INPUT WOULD HELP

[mojoe2878]

if it was locked up for a while, them i would think there is surface rust in the top end and if its not getting oil then a passage could be clogged.

[EXrider65]

It was only locked up for a couple hrs But it does sound like a oiling problem to me also. Took it to a friend of mine to check it out