Yamaha Lowering Question: 2012 YZ125

I weigh around 145 pounds do I still have to install a heavier spring and adjust the sag after installing linkage kit and without adjusting them will I still get the lowering I want?

The 2012 YZ125 stock spring is a 4.7kg. At 145 pounds without gear + YamaLink the ideal spring rate is a 4.9kg to achieve 1.5" lowering at 100mm sag. If you do not want to get a heavier spring we recommend setting sag at 94mm stock is 100mm) which would give you 1.25" lowering (100mm - 94mm = 1/4 inch less) and following our instructions for high speed compression and rebound adjustments. For off-road and trail riding this setup would be very good. For pure MX we'd put on that heavier spring with a 1.5" YamaLink at 145 pounds.