Fuel mix and changes in elevation...

Ok, this may seem like a silly question, but I might as well ask...

Since I have taken my bike from 1100 ft to 3900 feet, would I be correct in assuming that my carbs need to be readjusted? I finally had her out today for a VERY short run, and she was running sluggish. Hadn't run her since the end of January, after she sat for about three weeks, in Phoenix.

Anyway, thanks.

 

Yes, you are correct. You should drop one or two steps for the main jets, probably one step down (raise the clip by one slot) for an adjustable needle (or you'll need to get appropriate sized needles), and turn the pilot jet screws in a bit (check plug color for the idle settings).

 

Oh, I really hope I don't have to get new needles... I have to get this bike back on the road... gas in the pick-up costs too much. I'll have to start with screw adjustments, and go from there.

(Not that I have a problem DOING the work... can't afford the parts right now)

 

Keep in mind that all the screws do is adjust for idle and low power situations. Once you're into the mid-band, it's mostly the needle jets that are controlling mixture, and then, WOT, under load, is mostly main jets.

Now, you maybe could cheat... if you are still using the stock air filter, switching to a K&N will lean your mixture - it would probably get you halfway there. Although, that's money too...

You should at least look at one of the needles, though, just to see if it's stock, or an adjustable one from a jet kit.

 

I replaced one about a year and a half ago... don't think they're adjustable. Any idea how much they cost? Haven't found a junkyard in Missoula yet.