Hmmm, my experience with the LA 25 comes in RC trim but I would second the suggestion that you use the 9-4 prop for starters and let it wind up a little - you should get around 11,250 or so. The RPM's will not hurt it - keep it a little off peak and it should not run hot.

The oil content looks too high. I'm using 10% Wildcat which has 18% Klotz/castor blend. Sig at 20% is already pretty sloppy and extra 2% castor .... I just do not think that is doing anything FOR you, and could probably be dousing the plug and just generally getting in the way.

I'd say first task is to seek a full CONSISTANT run, then start propping up - probably a 10-4 PowerPoint or 9-6 PowerPoint would be the practical limits, RPM's will drop some but try to get the same kind of run - probably a very fast 4-cycle or "sloppy" 2 cycle run.

Dennis A