Hello!
Okey! Here we go!
First ....any engine with lose bolts will not function properly as air is leaking into the engine and will destroy the fuelsetting!!
Second any modern engine be it ABC,ABN or AAC does not requiere any long break-in. Only a couple of tanks is enough to obtain a god setting!!
Third any engine that stops rewing for a moment in the air, at full throttle, is set to lean ( the engine does not get enough fuel and gets to hot)!!! This symptom is developing either by setting the fuelneedle to lean on the ground or the engine overheats by other factors like to big prop, old fuel, to high compression , to low compression, to much nitro, not enough nitro, wrong glowplug or somthing wrong with the tank installation (too large tank, holes in the brass tubes) etc etc.

As for the mVVS with minipipe it is of vital importance that you run a cold plug; either a Rossi 5 or 6, that is if you have the short minipipe (No 3246).
This pipe is only working at high rpm:s above 15000 rpm and I recommend a 9x6-9x7 APC prop! Expect 17000-18000 rpm with these props and 80/20 fuel 0% nitro), do not run the engine on more than 10% nitro.
If you have the longer minipipe (No. 3248) which works between 10000-14000rpm use a 10x6-11x6 APC prop and not higher than 10% nitro. Glowplug could be anything...like a Enya 3-4 or OS 8 or Rossi 3-5.

As for setting the needles ......The description myaeromodelling gives is probably working but it's not what I would like to recommend to anyone because of the risks involved in using the electrical starter and adjusting the idle needle at the same time..

Instead do as most of us do......start the engine at idle (the idleneeddle schould be turned out a few turns, on the MVVS standard carb the distance between the point of the idle needle and the fuelinlet orrifice should be appr 1/2-1mm at fuel throttle
opening... then give full throttle......take away the glowplugcap....and adjust the highspeed needle (here you must learn to hear what the engine demands...to lean setting or to rich...listen carefully) set it below peak power so that the engine does not owerheat.
Then ..and first.... then throttle down and set the idle
needle...here you have to be careful and listen to what happens when you give full power...if the engine hesitates for a moment ....the idle needle is set too lean!
If on the other hand the engine bludder, hessitates, puff and smoke ..then the idle needle is set to rich...and has to be turned in somewhat....this is easy to do for most people who's been active in the hobby for a couple of years but could be a little difficult for a newcommer to master in the beginning.


Regards!
Jan K