Idle Speed Questions

[loply]

Hi folks, strange subject I know, but none of the books Ive ever read really discussed it.

What effect does putting the idle speed above normal have?

Does it change how the engine takes up slack in the drivechain etc when cornering in first gear?

How would it feel different when cornering with no throttle, if you had a really high idle speed (ie 3000 or so)? I guess it would unload the front more?

Does the way the carb works mean that increasing idle speed changes the fuel:air ratio at all?

Also, race engines idle at speeds like 6,000 right? Does this not wear the engine heavily when its cold?


Just something thats kinda been on my mind all day
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Yamaha SZR660 Caution to the wind, the throttle pinned!

[cunni]

You might suffer from loss of engine breaking if you do this?!

All I know about this one is: I need to tune my TL1000R, as I stuck various performance parts in and now it ticks over at 3000rpm. Sounds absolutly mental, but I know it'll feck it up, so it's still off the road!

I wouldn'tmess with idle times unless your going from summer to winter riding or vice versa!
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TL1000R Parts For Sale!

[loply]

Why are summer and winter riding idles different like? Just higher for winter?
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Yamaha SZR660 Caution to the wind, the throttle pinned!

[cunni]

This might not be true any more, but on older car's I've owned it was. Newer (digitally injected) bikes probably don't need changing, butolder ones with carbs could probably do with the idle time adjusting to a greater tickover for winter. Not too much mind, you don't want it revving like stink!

Oh year, You olny really need to adjust the idle time if you notice it nearly cutting out at stand still or if it revv's too fast.
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[8316]

ok, i might only have a little 125, but when i was playing with my idle (very,very easy) i could lose a noticable amount of engine braking when going into corners
well, thats my experience. means i went flying to corners....
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Now own a Fireblade!! Speed Limits? Bah!

[Dom_]

I noticed my engine was idling super low this winter, about 1k, just stuttering ready to cut out. It needs adjusting but i can't be arsed.

[stinkwheel]

If it is set too high, the bike will keep runnng on when you close the throttle to slow down. It will also be a lot more likley to overheat when you stop.

If it is too low, the bike will keep stalling when you stop.

Set it according to the book or adjust the idle down to where the engine starts to stutter then back up a wee bit from there so it maintains a steady tickover without offering to cut out.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[DM]

1,500 - 1,800 rpm is a good range for most conditions.

[stryker]

Agreed, my FZR idles around 1250 - 1500 depending on air temp and humidity.
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Now what?

[cunni]

bloody hell, my TL idles below 1000rpm, around 900 usually, except for the recent mods, I still need to get it back down from 3000!
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[AD]

My SV650s idles at about 1000rpm too, may be a twin thing or maybe talking rubbish.
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It was like that before i got here!

[Frost]

Typicaly the tickover should be proportional to what a bike revs to.

something with a huge etuned engine that only rev's up to 6k, would only need a tickover of about 800rpm. where as so shit hot screaming race bike needs a much higher tickover.

My bike ticks over at just under 3k. very high i know, need to do something about that!

[dodsi]

ER-5 idles at 1K

[stinkwheel]

It is more to do with the length of the stroke, a long stroke bike will tickover at a slower rev speed although the piston velocity is probably similar.

If you ever get the oppertunity to listen to an old slope-engined Panther 650 single (a mans bike!) which has a hugely long stroke, you can hear the individual detonations. Compare this to my modern 660 single which has a comparativley short stroke and ticks over at around 1000rpm (same engine as yours loply), a 650 twin will tickover higher still and a four even higher. The piston is moving at the same speed but takes longer to cover the distance involved in an engine revolution.

At least, that is my understanding of it.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Jrod]

I could of really done with this when I first joined this forum, my first question was about idle revs and no one replied! Guess thats what happens when you post in the workshop section.

[Kickstart]