Is ANY idle increase bad?

[Guest]

OK, I've put my top end back together. All of the following are less than a year old (new OEM):

All four intake boots
All four airbox boots
All four airbox clamps
One intake boot clamp (didn't match - they all tighten)
All intake O-rings

I adhered the factory weatherstripping between the airbox and filter housing, plus added weatherstripping around that. Added weatherstripping to the filter housing lid. The whole thing should be tight as a drum.

Cold idle (off choke) = ~1200
After riding around a while (15 mins.) = ~1600

Am I missing something? Is that OK? Was under the impression that idle should be totally flat hot/cold. It's not, say, 2500 like it might have been before. Then again, my test ride was not that long. Might need to take it for a longer one when it gets warmer...

[Larry D]

The bike should be fully warmed up before judging any tuning. Get completely warmed up, adjust the idle accordingly. The enrichment circuit (choke) will keep the RPM's up until it's warmed up enough to idle on it's own. This may take some trial and error between idle air screw adjustment on the carbs and the master idle contol knob. Sounds like you have it very close though.

[waterman]

My 650 daily driver will idle at roughly 1000 cold and no more than 1200 after warm. I haven't worked on carbs in over 3 years and checked valve clearance last year.

I agree that your bike may be idling high. I think they recommend 1100 +/- 100 rpm for idle. Try this, start and warm up until driveable, take off for 10 minute ride and then adjust idle back to 1100 or so. When cold, start again and see where it idles, if it idles.

I know in my case, I have the pilot screws (or whatever we call them) adjusted slightly richer than absolutely necessary. I went with maximum highest idle and then used colortune plug to just slightly rich. I can start at half choke and ride off with no choke in under a minute for almost all sane driving temperatures.

[mike_of_bbg]

I think that's where I'm at right now. 1k cold (getting it off of choke pretty quickly), 1.2k hot.