Excessive timing

[retal052]

Hey guys,
I have a datto A14 engine and it requires excessive advance in places to get power.

The timing above 4000 is set to around 40deg. Full load
at 2000 round 29deg. Full load

I was told to tune ignition by advancing till it pings, then back it off.
how far is too far.

also what is a good timing for idle. mines sitting on 27deg.

Thanks in advance....lol advance