Hmmm,, I must be doing something weird because I usually see the same, if not better performance from my rebuilds(done right). The ones I have done are still running strong(one has over 400 hours) except for one that was ran hard and no oil(forgot to add to gas at fill up) and one that was just not maintained and abused.( I have only done carb motors but if done right, will be just fine for a long time).