Can someone explain to me where they install. What weight and what are the advantages vs. disadvantages of different weight? I have an '03 yz450f that i am converting for trail use also. I am unclear as to what, how, where the flywheel is and goes. I was assuming the flywheel is the gear behind the clutch basket (like on a car). But I see yamaha, honda, and for all I know all the rest of 'em. Label the magneto as the flywheel. Please help. Thanks in advance.