Can you be more specific? The amount of cum that displays on the female, the amount of cum that is generated when you orgasm, the amount of cum that can be held in the mouth, or something different - it isn't clear what you want to try to do.
Cum displayed on female:
The loader already came with a Keys.swf file to set-up hotkeys for features like preventing the cum from disappearing. If you use the hotkey that you set-up, then you can accumulate as much cum on the female as you want (and you can still use the game's remove cum if/when you want to).
Properties of ejaculate:
There are a lot of settings you can play with in the settings.txt and they are explained in the Setup Guide.txt - adjusting the correct things can make the amount of cum in an ejaculation appear to be slightly different, although this doesn't directly change the number of ejaculations that happen when the orgasm is triggered.
Number and size of ejaculations in an orgasm:
There is a mod for this: morecumspurtsV2
You'll have to go the the loader imports board and read sby's imports thread (it's stickied at the top) to get the link. He has a video that will explain how to set-up mods.
