engine Temperature

Every time when I check the eng.Temp with LEd gun after run for a short time, it seemed so high like 150℃ and up.What is the problem of my engine? I have to adjust the needle to more or less oil,but the problem still there. Hope some big brother can help me to solve this problem.

what engine and fuel u use

Is it a new engine?
If so,
take your time and let it break in first.
It's normal for a new engine (especially a big engine) to reach 150*C.

Thank you so much for help anyway, big brother! It's still new perhaps, I bought it from US 3 months ago and run it for a very short time (because it didn't run properly, start and die always). Just today(9-23-07) It runs better but still overheated.  Should I have it break-in again or try to run it gently? It's a Vertex .18 American Engine. And I am using 20% oil. I have open inside to check, it seems ok, black but still smooth on the side of the "c-tone",  no sign of scratch, is it ok? I am a beginner and know nothing about how to adjust the needle, how many turns should I turn the needle?