TBparts - 186cc Big Bore Performance Kit (64mm) and Oil Cooler Kit: This is the biggest grom bore kit on the market at 186cc that does not require case boring. Bolt right
KIT CILINDRO BIG BORE CON TESTATA BENELLI 491 50 NAKED 2002 ATHENA 070200/1 47,6 MM
BIG BORE Cylinder Kit 57mm Bore kit Upgrade to 150 cc for Benelli BJ125-3E TNT125 TNT135 TNT 125 135 154FMI-7 Performance Kit - AliExpress