tony0707

The St 51 needs a -long --break in period , for it to develope its full power
One of my longest break in runs ,i can remember ,to get the engine to transition ,to get the NVs set correctly , on a bench
About a 1/2 gallon or so
Do realize during break in ,the cool down period between engine runs , is as important ,as running the engine itself
The engine must be completely cool ,at your next start up to evaluate your NV settings and see if they need adjustment ,again
If an engine starts to run hot and odd (because it was run lean) let the engine cool down completely ,then start it and reajust the Nvs
The pinch the tubing test, will run the engine up to max RPMS ,on the high and low speed NVS
Record the sound in your head and run the engine 2-300 off the max RPM ( SB 2-3 clicks richer ,than max RPM )
My average idle is in the area 1000 RPMs ,on a tach ,based on wind speed down the runway ,on a given day( 1000 WB for little or no wind )
I do run 15% in all my glo engines , as well as my 51ST ,and it might be my K&B 1 L plug ( with an idle bar) that allows me to do that , not sure
It might also be that , that is what i broke the engine in on ,so the beak in is based upon the heat the 15% produces to seat the piston and linnner
i never change the nitro percentages i run in any glo engine ,as the heat produced by different percentages ,determines the clearences between the piston and cylinder wall

My 51 is a beast , with 61 power in a lighter engine
Do not run any motor larger than the 51 ,in a 40 size airframe
The down side , of to heavy an engine , is your inability to land as you should on final as the plane will drop out and stall from the nose weight ( overloading the wings lift ability,when in a glide )
60 size engines ,will not fly a 40 size airframe any better --overall -than a 46 or 51
I spent many hour trying to do that ,with less than good results
The bottom line is ,your final approach , touch down and bringing you plane to your feet ,is still one of the best parts of the flight ,and that enjoyment is lost with to much engine weight up front ,as you will be stuggling to control the plane when it is in that phase of the flight with the heavier nose weight
Just kills the final glide
Enjoy