Fuel, mixed with oxygen, burns at a constant rate and produces pressure as the gasses expand. The optimum mix of fuel to oxygen ratio for petroleum is 14.7 parts oxygen to 1 part fuel and is known as the stocimetric ratio. So this is kinda a fixed variable. Add more fuel/oxygen and the rate...
Lets talk about outboards that in general run around 600RPM at idle to 4-5000RPM at fun speeds. For most of us I would imagine. Starting at the low end, Idle. And I'm targeting this at 2 Stroke owners, as this is where the issues most lay.