I wont dispute that the stock timing dampens performance, or that advancing the timing will improve it. I am actually not mechanically inclined enough to support or dispute this theory. I will say this: Many people think that the people that build these engines must be mechanically inept, because there are so many things about these engines that are backward of what we would expect in a performance-driven market. But I say this: these engines are designed to do exactly what they do. In my very limited understanding of this subject, I would propose that the timing retardation probably has to do with two things. One is speed. are they purposely trying to limit how fast you can go, just for the sake of limiting you? I doubt it. Most countries have laws on how fast bikes can travel, and what kind of power they can have driving them. not to mention the speed limits. In america, bikes are not allowed on highways. in most residential areas, the speed limit is 35 or less. the purpose of these engines is that they are legal almost everywhere for the most part because they dont break the speed limit. even if the engine isnt legal in your area per se, you probably wont get pulled over because you arent breaking the speed limit. here in pa, any motor assisted vehicle must be registered. I ride illegally. I never get pulled over and I pass cops all the time. Im not breaking the speed limit, so they dont mess with me. also I ride in the shoulder, so im not even interrupting traffic. another reason for the retarded timing probably has to do with mileage. a big attraction with these engines is that they get ridiculous mileage. bet if you change the timing, you wont get the same mileage. again i say, these engines were designed and engineered to do exactly what they do. the people that design and make them arent inept, they just dont make them to do what you want them to do. mods are cool, but a stock setup takes less work, less maintenance, less time, less energy, less money, and can probably be expected to live to its full life expectancy, whatever that might be. personally, i dont want to break the speed limit or get less mileage.