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Discussion Starter #1
Bike group rideout today and it's usually long n quite fast. about 200km into it I noticed every time I pulled the clutch in the revs would sit at or rev up to about 3-4000 rpm.
Now I did have something similar a few weeks back (when letting off the throttle it would take ages for the revs to drop but they didn't run up, so would hold too much speed going into corners) but was unable to recreate it since then.
Now today this lasted maybe 30 minutes, we'd stopped for grub for about 45 minutes and after that it seemed fine. Now originally I thought it was the throttle grip but I tried quick downshifting and that still works so it doesn't seem like it's getting an input from the throttle itself as this stops you from downshifting.
Both times these issues have happened it has been quite hot here, the bike getting up to a bar over half on the temp gauge but nothing more than that.
Any ideas folks, gimme some ammo to take to the dealer, due it's 12,000km service now anyway.
Ta
John
 

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vacuum problem?
+1

Next time this happens, pull over and open the tank cap. If it's hard to open or you hear a sucking sound :naughty: your tank vacuum hose is probably pinched or dirty.
 

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Discussion Starter #4
Cheers fellas, will give that a go next time I'm out.
 

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My money is on the oxygen sensor.
A fast ride sees me needing fuel in 150km :)
 

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Jogort...is the bike actually at higher revs, or is it just indicating higher revs?

The reason I ask is that the 1090RR has an issue where the tach will sporadically add 3k to the revs because of poor electrical connection at the back of the dash....
 

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Discussion Starter #8
Jogort...is the bike actually at higher revs, or is it just indicating higher revs?

The reason I ask is that the 1090RR has an issue where the tach will sporadically add 3k to the revs because of poor electrical connection at the back of the dash....
Definitely at higher revs mate, can hear it and feel it as well as seeing it on the dash.
 

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Why would a vacuum in the tank cause the engine to rev? Don't get it.
The fuel pump has to work harder and can't get enough fuel into the cilinders. On the other hand there is just as much air going into the cilinders. Too much air for fuel = higher revs.
I played with 2-strokes back in the day. :)
 

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Definitely at higher revs mate, can hear it and feel it as well as seeing it on the dash.
Hi Jogort,

I think I know what you are talking about.

This is what happens to mine. See if you agree

Symptoms: The revs do not slow down as quick as the bike usually does. It almost has a loose feeling to it. When you let off the throttle in gear, the engine braking is very, very weak. When you blip the throttle in neutral (or clutch in), the time it takes for the engine to get back to idle is longer.

Personal root cause: Excessive engine braking. Well, no so much 'excessive' but aggressive I guess. If I am travelling at speed and I need to slow down to 50mph for example, I'd front brake and blip down to 3rd. If I leave throttle closed and allow the engine and front brake to shave the rest of the speed down to 50mph, the engine suddenly 'let's go' and its almost as if it has lost compression. That's when the symptoms kick in.

Personal workaround: At first, I assumed that maybe I was taxing the engine too much and decided (in above scenario for example) to shift down one more gear, to relive the engine a little. I also started pulling in the clutch towards the end of my deceleration to relieve the engine. Now I just ride how I was in the beginning, but instead of closing the throttle and holding front brake, I just hold the throttle open just a little. I hardly ever get this issue now.

Would be nice to understand from the pros as to what is happening here.

By the way, if/when it does happen, I just carry on, but a little more reserved and it sorts itself out.

It almost seems like the engine is kicking in a safety mechanism to protect itself, not too sure.

Erm, if this is not what you are talking about, then just ignore my post

:naughty::naughty::naughty:
 

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The fuel pump has to work harder and can't get enough fuel into the cilinders. On the other hand there is just as much air going into the cilinders. Too much air for fuel = higher revs.
I played with 2-strokes back in the day. :)
Not in a pressurised fuel injected system mate.
 

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Discussion Starter #13
Hi Jogort,

I think I know what you are talking about.

This is what happens to mine. See if you agree

Symptoms: The revs do not slow down as quick as the bike usually does. It almost has a loose feeling to it. When you let off the throttle in gear, the engine braking is very, very weak. When you blip the throttle in neutral (or clutch in), the time it takes for the engine to get back to idle is longer.

Personal root cause: Excessive engine braking. Well, no so much 'excessive' but aggressive I guess. If I am travelling at speed and I need to slow down to 50mph for example, I'd front brake and blip down to 3rd. If I leave throttle closed and allow the engine and front brake to shave the rest of the speed down to 50mph, the engine suddenly 'let's go' and its almost as if it has lost compression. That's when the symptoms kick in.

Personal workaround: At first, I assumed that maybe I was taxing the engine too much and decided (in above scenario for example) to shift down one more gear, to relive the engine a little. I also started pulling in the clutch towards the end of my deceleration to relieve the engine. Now I just ride how I was in the beginning, but instead of closing the throttle and holding front brake, I just hold the throttle open just a little. I hardly ever get this issue now.

Would be nice to understand from the pros as to what is happening here.

By the way, if/when it does happen, I just carry on, but a little more reserved and it sorts itself out.

It almost seems like the engine is kicking in a safety mechanism to protect itself, not too sure.

Erm, if this is not what you are talking about, then just ignore my post

:naughty::naughty::naughty:
I'd say it's pretty much the same the first time I had this issue. Letting off the throttle and the bike takes for ever to slow down or when clutch is pulled the revs take a good bit longer to drop but I've not been able to put it down to any sort of riding style as I've not really been able to re-create it. I'd say we ride similarly, I use engine braking a lot but only had these symptoms once.
The 2nd time it was much more like revs staying at or climbing to 3-4000rpm when clutch was pulled in, obviously not good when slowing for corners and then the bike wanting to accelerate itself.

So if you don't think it's to do with vacuum etc Donsy got any suggestions? Will be a while before I'm able to get it to the dealer unfortunately, had it out for a 70km blast today and the bike was faultless....gggrrrr:thewife::ahhh:
 

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I'd say it's pretty much the same the first time I had this issue. Letting off the throttle and the bike takes for ever to slow down or when clutch is pulled the revs take a good bit longer to drop but I've not been able to put it down to any sort of riding style as I've not really been able to re-create it. I'd say we ride similarly, I use engine braking a lot but only had these symptoms once.
The 2nd time it was much more like revs staying at or climbing to 3-4000rpm when clutch was pulled in, obviously not good when slowing for corners and then the bike wanting to accelerate itself.

So if you don't think it's to do with vacuum etc Donsy got any suggestions? Will be a while before I'm able to get it to the dealer unfortunately, had it out for a 70km blast today and the bike was faultless....gggrrrr:thewife::ahhh:
So no high revving when pulling over? Then it's not the vacuum as this will only sort itself if you shut her down and let the vacuum disappear.

Too bad, that would have been too simple. :bawling:
 

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Discussion Starter #16
So no high revving when pulling over? Then it's not the vacuum as this will only sort itself if you shut her down and let the vacuum disappear.

Too bad, that would have been too simple. :bawling:
Yeah Lacsap, 2nd issue was highish revs when clutch in/in N etc but I've not been able to re-create it as yet.

Out of sync throttle bodies can cause this as well. Might be something to check
Thanks man, I'll add that to the list of things to get the dealer to check.
 

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I'm thinking something mechanical like the throttle spindle sticking slightly or maybe the servo that closes it. If its electronic they'll see it on the diagnostic.

I used to have a fuel injected Alfa that did this. The Italian tech I took it to shrugged and said 'something get hot - it stick....'
 

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Discussion Starter #19
Well it happened again today but in a kind of strange way. Rideout for about 40 minutes or so in high 20'sC outside temp and bike is running fine, so time to stop for a drink. The bike sits off for about 30 mins and as soon as I start the bike the revs are up to about 3500rpm and not dropping. It stayed like this for a good hour, every gear change you could hear it revving so as Lacsap suggested I opened the tank but had no issue getting it open and no sucking noises. The thing is as quickly as this comes it just goes, carry on riding and it's fine. I guess I'll have to try and explain it to my dealer in spanish when it goes for its 12k service, that should be fun.
I'm wondering if it's to do with the temperature here? it's been perfect all winter when the ambient temp is lower, direct sun temps here now can be bloody hot, clutching at straws maybe.
Oh and to add to the mysery after my Quickshifter getting fixed I adjusted my gear lever position and now the fecker doesn't work again. Had it all off n cleaned n checked connections and still nothing, bloody bike!!! but I do love it.
 
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