Winter Jetting
 

Now that the cooler weather is coming, and changes in air density will start to affect carburetion, can anyone out there provide me with some pointers as to how to jet my '10 EC250 ? As it is I am having enough trouble keeping the bike running clean during "normal" temps. What changes do we do for the colder days ? And can changing the plug from a BR8 to a BR7 help that change ?

All help greatly appreciated, thanks.

Resurrecting this thread because I have the same questions.
Planning on riding my EC300 in snow and wondering if I'll need to make jetting changes... Should I change plugs as well? Any tips or advice? My bike runs great right now in warm weather although the bottom could be a little smoother....

It depends on the temperature difference from your previous jetting. When I set up our 04 GG300 for ice racing I went up one pilot size, down one clip position and up 2 main jet sizes.

I think the GG manual provides some good temperature correction info.

Thanks, that gives me an idea where to start at least.

Leave the standard spark plug in, the BR8EG.

If you feel a difference in the jetting when riding in the colder weather then go a little richer.

Try the pilot air screw in a bit.
Raise the needle one notch (circlip one notch lower).
One size bigger on the main jet.

Don't forget your thermals!

Good luck and happy riding, Dave. :)

Thanks so much Dave. Gives me a great place to start. I'm starting to enjoy learning the ins and outs of jetting....

My bike runs perfectly in Minnesota summers (up to mid 90s & high humidity). I trail ride into early winter and have ridden in temps down to the low teens. I tip the bike to flood the carb, let it warm up thoroughly and then it runs exactly the same as any other temp. A few friends need to make a little adjustment with the air screw, but that's about it.

I bet your bike is probably lean in the winter and rich in the hot summer.