Hey there I’m having problems with my 2000 Polaris explorer 400 2 stroke..

I blew it up and lost all compression which is normal for a 20 year old atv.
i orderd a forged piston and did a top end rebuild and I had a very experienced mechanic help me. I am positive we put everything on right because after putting everything back together it started and idled fine. I went to take it for a ride up the street and it was smoking pretty bad, figured it was because I just put fresh oil threw it. Got to the end of my street doing quarter throttle (taking the break in process very seriously) and my temp light came on and seconds after a little pop and no compression again.. i have been told maybe my oil injection system is stuck closed and not getting any oil ?
Other then that I’m kinda lost and open to any suggestions.