I have a 2000 RM 125 that I am rebuilding, I pulled the jug off to slit the cases and I noticed that the powervalves are seized in the head. I have soaked the jug in wd40 and a diesel mix for days, wont budge. I have carefully tried to break them loose without doing any damage with no success. I have also put the jug in an oven at multiple temps multiple times and I still cant break them loose. I am open to any ideas and I hope someone else has experience in fixing this issue. I do not want to buy a new jug or a big bore kit because if I am going to put $1000 into something it will be towards a new bike. Any help would be much appreciated.