Mark,

In my opinion running a DZ for 12 to 15 seconds at full throttle static on the ground with or without the chin is hard on the motor and is more and likely running hotter in that situation than what the Manufacture intended.

The following is the recommended initial running procedure for the DZ series by the YS US importer.

1) Set high speed needle at 2.5->3 turns open, start motor at idle position
2) Run motor at a fast idle only for 10 minute intervals for 20->30 ounces of fuel (allow proper cooling between 10 running intervals)
3) After step 2 then run motor up to full throttle only long enough (few seconds) to set full speed needle (max rpms less 1/4 turn rich)
4) Adjust TX setting to achieve a reliable idle of 1900->2100 rpms
5) Go fly

Following this initial run-in procedure has increased my performance longevity and reliability immensely with the 160s and 170s I have competed with over the last few years. Also like others have recommended I suggest you upgrading to fuel containing 30% nitro with 20% or greater low viscosity oil to achieve ideal performance and lubrication.

My setup with the DZ 160 consisted of the following:
CoolPower Heli blend 30%
OS Type F or YS glo plug
APC 16.5X12 2bld @ 8500 RPM
APC 15X11 4bld @ 8800 RPM