Jetting for real(!) cold

2 replies to this topic
  • Ingvar

Posted December 17, 2002 - 04:35 AM


Hi, from frozen Moscow
What do you use for 5F(-15C), 14F(-10C)?

Pilot air jet
Pilot jet
Pilot screw
Main jet
Main air jet
Jet needle , groove position
Starter jet

PS: I know the carbs are different for different markets
(US, Europe, etc.), but i hope your information will help me
with my games with jets.

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  • Taffy

Posted December 17, 2002 - 10:51 PM



if you have a euro wr400f? :) then i would suggest that you go with my jetting from below but that you keep the very rich choke jet in to get the bike started. so a #62 or a #65SJ is fine.

once the bike is up and running the jetting figures below will run the bike at a good 'normal' temperature.

if i were you i would cover at least 50% of the radiator as an experiment. this should give you a good operating temperature.

how to tell?

well generally i would tell when i've STOPPED the engine. the click-click and clack-clack of everything cooling down. if it's hotter than normal; expose more of the radiator than before etc etc


  • Ingvar

Posted December 17, 2002 - 11:03 PM


I forgot to say, i've got euro WR426'01,
but i see your main idea about very rich choke jet and
'normal' jetting for the rest. I'll try and post my results
Thank you, Taffy


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