big bore kit

[markemark2k6]

my brother has an 06 yfz 450 & he broke the crank shaft so the motor is getting tore down & was wondering about what kind of big bore kit would be best for the money ?

[greenblood01]

The cylinder on the YFZ is nikasil plated, so there is no boring the stock cylinder. You chould have the nikasil removed and a sleeve put in place, or buy an aftermarket cylinder that will accept a larger piston.