I agree with Maclaren. My friend Jonhn had been running the 046 since there first intro. He alway's told me, and showed and proved to me, the earlier 046mag's, were lighter, and had more power. Reason being Im sure smog-epa, and detuning also why slightly heavier. We have two older 046 mag's at work, and two brand new ms 460's. All stock but the dp mufflers on all. The 046 mag has slightly more snap, and feels closer to my 044 in size weight. Not much but it's there. Also if memory serves me right the earliest 046's did not have the plate under the gas tank, to protect it from a thrown chain. That was an upgrade and could ad not much but some weight. John siad the old ones the thrown chain on a landing, punched right through the fuel tank, more than once. Epa smog will always ad weight, and detune look at the early muffler's compared to the new ones. It may take adding a dp muffler, and a retune on the carb, but stock for stock the early 46 had more beans, and was lighter I dont need a scale I can feel it.