Idle speed

[Whosthedaddy]

Very simple and random question, what should the idle speed ideally be?

FYI carbed bike so have an adjustment screw.
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Current : MSX 125 Past : CBR 900RR Monkeybike : c50 LAC : ZXR750 H2 : FZR600 : ZX7R P3 : YW100 : TRX850: Trophy 900 T309 : GSXR 600 L0: Monkeybike : XJ6S Whosthedaddy

[MCN]

800-1000

Edit: BMW S1000RR 1250RPM

You can normally set it to a non lumpy idle when cold choke on so it doesn't die when cold.

Then phaph about with it when it's warm after a good run.

You need 'the heat in the metal' not just a quick scoot or letting it warm up on idle alone.

Almost all machinery 'running adjustment' is adjusted when warm/normal running temperature as this is where the beast should be most stable normally.
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[CaNsA]

Depends on the bike, and the person.

Kwak suggest 1200rpm for the zxr400

Smiler prefers 4000rpm on a 125.

[RhynoCZ]

What motorcycle? I'd go with what the manual says, which for a ZX7R for instance, should between 1100 and 1300, +/-50 rpm.

The motorcycle would stall at 1000 rpm, not even talking about 800. I have it at about 1200 rpm (it's as low as it's possible for the bike to keep smooth steady idle with all the lights turned on, because there is a car like alternator).

EDIT: I was checking the manual so long, that CaNsA gave you the answer first. Anyway, the key is, to get the idle as low as possible, while still being smooth and steady. The revs doesn't really matter, it's more of a safety measure for those who are deaf or just plain stupid.

Too fast idle will excessively wear your first gear, too slow idle will stall the engine.
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'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[Kawasaki Jimbo]

Also consider whether it will respond to the throttle correctly. The workshop I used to go to was able to get a beautiful low idle but when I got home I would dial in 100rpm more because it wouldn't pick up smoothly from 950rpm.

[chris-red]

[RhynoCZ]

The rev counter reads 1000 - 1500 - 2000. The manual says +/-50 rpm for 1100 rpm, then +/-50rpm for 1300 rpm.

The wear; it's just something I tend to do. When I had my first motorcycle, the idle was sometimes sky high, I was too stupid to fiddle with it, and when I shifted the 1st gear from neutral, there was always this very loud bang. Then when I shifted the 1st gear at reasonable idle, it was just a decent click. From that I assumed a very fast idle is not good for the gear box, as the output shaft is not moving and the input shaft is spinning very fast. The opposite to it is, when you accidentally kick it in neutral, but still going aplenty fast, trying to kick it back in gear again without revving the engine to mach the speed of the input shaft to the output shaft.

Might be paranoid here, but I certainly don't feel alright, when I ''have to'' put it in gear from neutral, when the idle is sky high. When I accidentally kick it in neutral (thought I was in the third, it was the 2nd gear, still going at 15-20 mph, wanted to do full stop, but the situation changed) I always rev the engine before I try to kick it back into the 2nd gear. Once again, a personal experience with doing that the wrong way leading to a very distinctive bang noise.

Motorcycle gearbox is not a car gearbox. Just because you disengage the clutch, doesn't mean you can fiddle with the gears as you please.
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'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor