I suggest adding a bunch of fuel first. Then lean back to take off power at about 50 to 100 degrees rich of peak power/EGT, or under 1600 degrees. Or F/A in the 12s. We have people in charge of warping apex seals. You do not need to cover that again.

 

I sense a lack of check list. I detect more than one change at a time.

(a dyno room violation)

Is there at least a 50 pound CO2 fire extinguisher standing there with the pin out?

 

Timing at 20 degrees BTDC is fine up to 9,000 RPM on low octane pump gas. Remember pump gas burns a bit faster than avgas. We are looking for best cylinder pressure at about 50 degrees after TDC not 18 degrees like a piston engine. Turbo engines at high boost can be at 10 degrees BTDC. Too much advance kills HP and adds heat.  

 

Lynn E. Hanover

 

My tuning skills are improving.  With my dyno-prop installed, I was
topping out at about 4,000 rpm.  The spark advance was on the way down,
but the AFR was on the way up.  Way up.  To the point of lean cut-off. 
Right before the stumble, at 3800rpm,  I was burning approximately
5.25gph.  At an idle centered around 800rpm, the burn was about 0.6gph.