Can someone kindly help me out with these Merc #'s. I have a 1994 Merc 75hp Pro Series Tracker. Model 1075412PT. Serial 0G073793. The engine idles rough and I wanted to adjust the idle mixture screws. When I looked on the WME carburetor chart my 75 ELPTO carb #'s start with 33 not 29 as the manual states. Thus the idle mixture screws require different settings. Example, on the 29 the carb #1 preset is only a half turn out. Which carburetor settings do I use.