YX 150 help? Cases need split. Any upgrades?

New to the forum....having major problems with my yx 150 nitro motor. Never was right out of the box, was jumping in and out of third and locked up. Found bearing outer skirt in case when I pulled the first time. Upon another inspection after pulling clutch and oil pump, found these chunks...thank you oil screen!! It has broken a part of the case, but not completely. My ??? is should I send it to have it repaired or am I looking at a parts motor now?? Money wise.......have around 500.00 in it complete. What type of money to split this and repair? Also....heard it from a friend there is an upgrade to this weak inner case for these and it may be a common problem. Anybody??? By the way....the motor does still run great in all the other gears..thanks here are the pics