Whenever started with choke it goes to high revs, so I have to kill the choke after 2-3 secs. Usually it kills the engine, so I have to kick it again (with the choke), kill the choke as it starts, and the engine continue to idle normally (probably warmed up).

One more thing: mine  is Sherco 2012 and it has the switch for two modes of throtlle response, but honestly I can't see the difference. Is there any proper way to check if it works at all?  

If the bike is running fine in all other respects and it has always behaved this way on a cold start only another 125 owner can give you a answer, I find my 300 Evo revs high initially after a choke start but then calms down to a fast idle, i generally shut the choke off after around 20 seconds or so, like your Sherco my Evo has no perceptible difference between soft and power on the mode switch, I suspect it is only a thing at high revs, being a novice i don't really use the top of the rev range.

I have a 2014 Sherco 125 rear tanker.  Mine always revs high when using the choke.  Push the choke off after a couple of seconds.  If it starts to die then quickly pull the choke on for another couple of seconds.  Mine has done it from new.  I don't think it is anything to worry about. 

The power switch.  With a SLOW throttle I didn't notice any difference.  However when I refitted a QUICK throttle, it made the engine pick up faster to the higher revs (where the power is on a 125).

Edited February 4, 20188 yr by stpauls

The answers are relaxing and what's more important, are IDENTICAL. It's wintertime but the livin' is easy again. Tks guys.