I've got an '07 and I recently moved from California (near sea level) to Denver (the mile high city); since moving it's a lot harder to get the bike started and the choke does squat or makes it worse.  I've gotten to the point where I've cranked it until killing the battery.  I'm assuming the high altitude is making it run richer since there's less air here and I'm trying to figure out the best way to dial in my mixture.  I haven't noticed a substantial drop in performance while it's running so I'm not sure if I should just mess with the idle screw or change jets or adjust jet height.  Any thoughts?  For what it's worth, it has the CA emissions recycling system which might add to the richness.  Everything is stock. 

Thanks,
CJ

Have you took the spark plugs out to check the colour,if its lean you could poss` try an extra shim on slide needle/upping main jet by 10.

Quote from: JAY W on August 25, 2010, 12:15:12 PM
Have you took the spark plugs out to check the colour,if its lean you could poss` try an extra shim on slide needle/upping main jet by 10.

That wouldnt help him get it started.  At idle there is only the pilot jet and air screw and choke that effect it.  If you think it is too rich, did you try starting it with less/no choke?

Yes fair point,still worth checking the plug colour if hasn`t already.Also bad plugs can show up from not starting well.

No/less choke still has problems (again, it's impossible to start with choke; very difficult without).  I haven't pulled the plugs yet because the only way to keep it going was to ride it.  At first it wouldn't idle without dying.  Once it's been ridden a bit, it will idle for me.  But the last time I went to get it going so I could kill it at mid-RPM and pull the plugs, and I cranked it till the battery died without it starting.  It'll catch a few strokes on it's own, but won't sustain them for more than a minute or two.  I guess I wanted to see if there was a common fix that I could move toward so I could get it running.  Then once it was running, I was going to dial it in more precisely. 

Try cleaning your carbs out. If it runs better after it is hot, I'm inclined to think it is not too rich (maybe im wrong)

The way i think about it is as the engine gets hot, it heats the air coming in thus lowering the density =runs richer. So, it shouldnt run better after it is hot.  I kind of just thought that up, I did not read/hear it anywhere so i could be compleatly wrong.

Well, the heat wave here ended and now that it's a bit colder, the bike is running much better; I think this further supports having been running too rich.  For gits and shiggles I decided to put a binder clip on the hose running from the CA emissions system resevoir (that stores extra gas fumes when the bike isn't running, and feeds em to the carb when you first turn the bike on) and it's been running great since.  In fact, this morning was the coldest we've had and choking it helped a bunch.  I'm pretty sure the emissions system was the culprit.  I think the reason the problem would resolve after riding a bit was not due to the temperature but rather, the emissions resevoir would dry up after riding for 30 min or so.  Then it wouldn't cause problems until the bike sat and the resevoir accumulated extra fuel with which to flood my carbs.  I think I'm just gonna leave the binder clip on until I get the motivation to rip out the CA emissions system entirely.  Thanks for everyone's help. 

-CJ

Yeah, that's exactly how the emissions gear is supposed to work. You can't start it, so zero emissions!

If you get into that situation again, make sure your air filter is clean.  A pox on the CA smog junk.

prs