When I measured the amount of oil I added for my last tank of fuel I calculated it to be around 25:1 ratio. I added 500mL after filling 13L into the tank. My understanding that you want to be adding 1L per tank about 50:1 ratio. the markings on then oil pump line up exactly, and I've installed a spring which encourages the lever to relign the markings with ease when you let off the throttle. What do I need to change to get my ratio closer to 50:1? Thanks.