@Hybrid_Theory01 It won't be the gearing, it'll be the starter. It's the same as if you bump start your motorbike in reverse then it'll go in reverse.
So the kick starter mechanism probably isn't correct.
Although, I cannot visualise how this can be the case. I can't see how the gearbox can be assembled in such a way, so the only thing I can think of is the engine going around the wrong direction.