Here is the link to the profi web site..there is "quick start" and "Q500 instructions" on these pages.

http://www.flycontrolline.com/Profi%20Q500%206.5cc.htm <link

Also from Jim Booker
"The correct propeller for the Profi is the old 8.75x8.5 or 8.75x9W. The ground rpm will only be 16000 and it will not run at full throttle for more than 5 seconds so you have to hold the throttle at ½ until just before the launch. It stages on the pipe and goes very fast. Figure out the needle which you have to get close by flying the model and leaning until it hits properly on the launch. Too lean and it runs fine but not fast, too rich and it runs fine but not peaking on the pipe. "