Cold pipe problems? And jetting

[norwegian]

My friends 01 MM 700 seems to have cold pipe problems. If it's cold outside, say -15 -20c he always has to warm u the pipe again after a trail stop. Otherwise it will be low on power and stumble when he hits the throttle. I can't remember having anything like that on my 98 srx 600 and according to turk it did have some cold pipe problems. What's up with that MM?

What is the definition of a jet size

Is a main jet that is 142,5 2,5 jet sizes bigger than a 140?
is a 142,5 1,2 jet sizes bigger than a 141,3 or just 1?

 

[Turk]

Get him to turn out the fuel screws 1/2 a turn. Every 1.3 difference in jet size is about 1/2 diff. EG from 142.5-143.8 =1/2 a main jet size.