I just put a Digitron gauge on my 01 700 mxz, Stock pipes and jets, just ported it. The probes are in the y-pipe about 1 1/2 to 2 inches from each cylinder. My question is how fast should the gauge react when you rev the sled. Also what temp should i be shooting for when jetting?

Bomber says in various shop manuals and aircraft shop manuals that the probes should be 3.91 inches away from the piston. 3.91" = 99 millimeters away.

I don't have an answer really, but my opinion I think one should gain an experience and learn to read the piston wash first...then EGT gauge; Then gage your piston wash to the EGT gauge. Lots of guys move around their timing with keys, or trigger placement, stator placement or using a timing position switch.

I'll pull a little snippit out of a manual regarding EGT's.
Advancing or retarding ignition timing moves around whatever heat your engine is capable of making.
An engine is a heat pump. If you run advanced ignition timing you put heat in the combustion chamber where it is needed to make power.
Retarding the timing puts the heat out in the pipe. Think of an exagerated relative position of the piston and crank orientation between what you think of advance and retard timing. Think of where the spark fires the fuel.
This is why you could see EGT's go up on a dyno and power go down.
Some engine tuners rarely use EGT for tuning and would rather check piston wash.
The advanced ignition timing that most race engines responds to, put the heat in the chamber where it needs to be but by the time it gets to the EGT probe in the pipe it has already begun to cool. On a dyno, most people think something is wrong on the dyno when 900 degrees is the peak exh temp, yet the power is up.