Im sure im not the only one...but there is a spot on my saitos high needle where you wont get any rpm change for quite a few clicks. Whats this all about?

Four stroke engines will do that when you get to the right mix. If you keep leaning out, you are just running lean without any rpm gain. It's confusing if you're used to 2 strokes and hearing the big increase before dying.

yes i have noticed that, it kinda scares me that i can keep turning it with out noticing a difference in rpm....so i richen it till i can notice a slight drop in RPM, and makes a nice smoke trail

I have had this with my Saito 56. When leaning the HS needle what seems to be a peak is reached i.e. no rpm increase with further leaning. Thinking I had maxed out the engine (7700rpm or so) I left it and flew, engine was obviously rich so after landing I leaned the HS needle more (pinching the fuel line helps to confirm that the needle is still rich). After another (several) clicks the rpm starts increasing again. This is where you need dto go slowly - 1 click at a time and allow several seconds between clicks to let the adjustment take effect. Almost a full turn leaner the rpm was up to over 10 000rpm, now I richened back to 9700rpm checked the transition and been great ever since, minor adjustments for temperature only.

Excellent way of explaining the whole thing andrew,thanks from all i hope