Mark,

The problem you will have is allot of engines are already at max power before full throttle, especially 4 strokes and 2 stroke gas engines and if your mechanical throttle connection/resolution is off even a little then you may be well over 4000 long before 1/3rd throttle

How I break in my Saitos is set the needles like the book, start it and just increase the throttle to get a little higher idle, jsut a click or 2. You do not need to get to 4000 exactly, less is good in this case, besides at the settings you are gonna be at, you'll be burning around 2 ounces of fuel per minute

As an example my YS110 reaches max rpm at about 1/2 stick so I had to setup a throttle curve in my radio to make the stick reach full throttle by rpm at the end of the stick travel, but if you look at the carb, it's only open about 2/3rd's the way. My resolution is just about perfect. At full stick, before I set the curve, my carb had just went to full open

2 stroke gas engines are even worse.

A tach is a must for a 4-stroke.