:welcome:
Before we start, we need to know a few things.
Model number of your mower
Model number of the old engine
Model number of the new engine
Make of carb fitted to new engine
Was the new engine new or used
What exactly do you mean by flooding
What exactly did you do when you cleaned the carb
Did your old mower have a fuel pump
does the new engine have a fuel pump.
Hooking a gravity fed carb to a fuel pump can provide a higher fuel supply pressure than the float can cut off.
I fell into that trap early on when repowering a ride on with an engine from a walk behind.
Took me nearly a year to work that one out but I got real good at disassembling carbs.