RE: NEW DLE 20cc Gasser! (Data & Links 1st Post)
Guijs - 3/32 is the correct tube size for this engine. If it's running this poorly on the ground I would not be flying it until I got this problem fixed. First, a 15x12 is a bit much prop for this engine. 15x10 \ 16x7 \ 17x6 are all good props. Also, Master Airscrew props are not very effecient - better to go with APC for now, and XOAR or VESS when you're confident you won't ground strike as much. I'd suggest going back to factory needle settings, find that "how to tune" link and start over. Not sure what the default settings are - maybe someone here knows. I think it was LS - 1.5 and HS - 1.1, but not sure. These needles are very sensitive, btw - you only want to move them a click or two at a time.
Are you using 32:1 oil ratio? When you're running at WOT on the ground, did you try closing the HS needle, slowly? For some helpful information on this engine you can look at the very first post in this thread. One thing you'll see there is to expect around 9,000 RPM at WOT with an APC 16x7.