One cannot increase the diameter of a gear without changing at least one other aspect of the gear design. If the original gear design has characteristics to which you object, it's important to correct the design, rather than make possibly-incorrect assumptions about a solution. In this case, your suggested solution of increasing the gear size without changing other appropriate features is likely impossible.
There are "mathematical" ways to generate gears that should solve your difficulty. I purchased at a reasonable cost Gear Template Generator program for the rare times I have to make a gear structure.
There are other programs which appear when searching for "gear generator" and also "free gear generator." If you are comfortable with Fusion 360 (free hobbyist version), there are a number of links for add-ons and various approaches to creating gears, although I've not researched them at length.
These generators produce involute gear shapes, which is how problems are avoided. You could also search for "how to make involute gears" which I have done. The resulting links provide clear design criteria for "drawing" your own gearing. This method involves using a draftsman's compass and other drawing tools. With today's computers, that's not the most practical method, but provides for better understanding.
Image from linked site.