Good evening I rebuilt the carbs on my 50hp mer outboard and I replace the inlet valves on both carbs. I reeinstalled them, got it running and tried to adjust the bottom carb and got the bottom mixture screw turned all the way in no change. The top carb does change, so I plan to removed them again because I am wonder about the float setting on the bottom carb. What is the best way to check the height adjustment. Also when you set the boat up for he winter what is the best way to prevent carbs from varnishing up. Thanks for your help Guy