Hi Jamez, welcome to Outdoorking.
We need more information on what you mean by "locked up". If it locks up in either forward or reverse, but not both simultaneously, and if it is capable of being unlocked, the problem may be in the clutch linkage. On the other hand if both forward and reverse are permanently locked up, it sounds like assembly error in the center of the clutch axle. We need to understand the malfunction before we can suggest possible causes.
