28m707 engine rebuild

When I am trying to replace the crankcasecover the bolts are all same length but three seem to be to long. When I checked an exploded parts diagram the bolts are all the same length so does anyone know where I am going wrong. Guess I should have paid more attention when disassembling, thanks in advance

the bolts have a thread locker on them from the factory. Unless cleaned out of the blind holes, can build up in the bottom and cause the bolts to bottom out. Try cleaning the bolt holes and threads