The 2005 YZ250F crank and flywheel are larger and heavier than the 2001 YZ250F crank and flywheel. This means that the 2005 crank and flywheel will need to be balanced with the 2001 engine. Additionally, the 2005 crank and flywheel will require different bearings and seals than the 2001 crank and flywheel.
It is important to note that this modification is not recommended for beginners or those who are not mechanically inclined. If you are not comfortable with making these modifications, it is best to have a professional mechanic do them for you.
