I just about have one of these broken in now (about two gallons of fuel). I was also new to Saito and 4-strokes and breaking it in was quite an adventure. I am glad to hear that you have yours mounted on a board. If I had it to do over again I would have done it this way on a board, instead of on the plane:

Saito says to start it up the first time with the main mixture adjustment 4-5 turns out and the low speed mixture screw flush with the surface. This is an extremely rich condition- it will run rough, go through fuel very fast and make quite an oily mess. Make sure that the motor is very well primed, especially at first. If the motor gets lean it will backfire quite violently. I destroyed two props and an aluminum spinner due to backfires until I recognized this trait. If you plan on using an electric starter then use a plastic spinner until you have the motor adjusted and stable. And use a locking nut and make it very tight!

After you run the first tank or two I would begin adjusting the high end and use a tach to get the RPMs up to at least 8500 RPM. This should correspond to the mixture screw being around 2 to 2 1/2 turns out. Then I would go back to the low end mixture and start turning it in until there is no noticable drop in speed at idle when the glow plug is removed. You will probably have to turn the screw in around 2 turns to reach this point. Don't be in a rush and let the motor go through a few more tanks of fuel as you adjust it.

After about a gallon of fuel you should be able to lean the motor to a "normal" condition, which should be around 1 1/2 to 1 3/4 turns out. Then go back to the low speed screw and try turning it in further to get a smoother idle and reduce fuel consumption to a sane level. If you get too lean then the motor will want to backfire or quit when you advance the throttle. You should end up with the low speed turned in 2-3 turns from its starting point.

The motor really loosens up with time and RPMs will increase for a given setting as it breaks in. After two gallons I am flying it at around 9400 RPM peak with a 15-6 prop. And it goes through a 16 oz tank of fuel in a little under 20 minutes.

Good luck!