I have the repair manual with the numbers

I have the manual with the carb measurements but dont know where to measure. Where do I measure venturi bore? Also throttle bore (which side of carb),main jet air, and slow jet air. I purchased a 20hp carb to upgrade my 2015 mfs15d to 20 hp. I also suspect my ignition coil but I cant test how the manual wants me to. The boot on the plug wire coming from the coil wont come off. Between the red and black wire I get ohms within specs. When I test between the black wire and inside the boot I get OL. It is a fluke meter. I forgot. Where is the main nozzle bore. Thank you so much in advance for any help you can give

As I mentioned in your earlier post, verify that you indeed have a 20 hp carb. No clue about bore diameter.

thanks for the reply Paul. I found all the carb spec #'s on page 37 of my service manual. I just dont know what exactly to measure. I really think they sent me the wrong carb because the main jet plug doesnt have a hole in it. It seems to me that the difference in the venturi bore should be obvious without having to measure. Thanks again

Yes, the 20 carb will look bigger.