back when I had a mc 16 it had no speed restriction and when I stuck on a set of free flow scilencers and mc21 carbs it had heaps of power and would easily reach 200ks which was redline in top gear anyway , after it blew up cause of a blown head gasket I put mc21 cylinders on it cause that was what I could get and they made no difference , the bikes main downfall was not power but tyres