basenjib123
New member
I want to switch from regular yamaha gear oil to synthetic. I have 2008 Yamaha F150. Do I need to flush the gearcase out first before adding the synthetic? Is Quick Silver Mercury Marine SAE 90 High Performance Gear Lube satisfactory in this motor? The Mercury stuff is just far easier for me to obtain around here. Thank you and Happy Memorial Day...Please remember those whom sacrificed for all of us.