Engine revs up high after cold start

Hi,

quick question: Is it normal that my Z650B (VM24SS) at cold start with full choke revs up 1-2 seconds after start to over 3000 rpm? No trottle of course. Every time I need to reduce the choke quickly to keep the engine at a reasonable speed for warm up. It starts best with full choke when cold.
Apart of this everything is good with the engine. 

Cheers
Joerg

Yes! That's normal.

As zed1015 mentioned, it´s normal. KZ 650/900 VM carbs has not a choke but an extra fuel enrichment cricuit that by pass the normal idle adjustment. It´s like an extra little carb running more fuel and higher idle during the cold start period against the condensation losses of fuel on the cylinder walls.

Thanks zed1015 and scirocco! Yes, I saw the choke plunger during carb cleaning which bypasses idle mixture.
So I keep my left hand near the choke lever at cold start. 

Cheers
Joerg

wrote:

Thanks zed1015 and scirocco! Yes, I saw the choke plunger during carb cleaning which bypasses idle mixture.
Cheers
Joerg

To be accurate the choke doesn't bypass the pilot circuit/idle mixure.
It just adds more fuel for cold starts.
The pilot circuit remains active at all times and adds to the entire fuel curve.
The overall jetting is a stack up of all the fuel circuits.

Have always  the same with my VM29 smooth, is normal behavior for VM carbs.