Yamaha Dirtbikes
i am rebuilding a 2001 yz125, and i bought a 1998 cylinder jug. the bore and stroke is the same from 94 to 02, but the compression ratio is off. the ratio for the 98-99 is 8.9:1 with the pv open and 10.9:1 with the pv closed. the 2000-2001 is 8.7:1 with the pv open and 10:1 with the pv closed. i...