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Discussion Starter #1
Doing a Toy Run on Sunday we were on our way home when I pulled up to a set of lights, dropped the bike into first as I approached and the revs sat at 2000 rpm. Put it into neutral and it dropped back to normal. I've replicated the same behaviour today with the bike and it's like this...

Start bike, normal rpm in neutral.
Put it into first, let clutch out slowly no throttle and it sits at normal rpm.
Rev the bike above 2000 rpm and let it drop back, it stays at 2000 rpm clutch in or out.
Put the bike into neutral and it drops back to normal.

We tried it in second and it behaved pretty much the same although if you rev the engine a couple of time it will drop back to normal again.

Any ideas? All the bike engineers I've spoken to are stumped. :confused:
 

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Sounds like it has something to to with the gear sensor and fuel injection not being in sync.
Don't know much about this myself but wait a bit and the real experts will be along.
Ond, Dave, Chef, care to have a go?
 

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Does the temp gauge read ok?

Sounds like it's hovering around the same revs as when the cold enrichment is on.

Do the 955s have a gear sensor? I know the 1050s don't. Apart from the neutral switch.
 

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Discussion Starter #4
Does the temp gauge read ok?

Sounds like it's hovering around the same revs as when the cold enrichment is on.

Do the 955s have a gear sensor? I know the 1050s don't. Apart from the neutral switch.
Temp gauge reads fine. There is no engine warning light and nothing appearing to be wrong.
 

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Sounds like a sticking throttle cable. Mine is doing the same thing (2K 955 ST)so I got a new cable, but have yet to fit it. The only other thing I can think is that there may be some movement from your clutch outer cable that is moving the throttle cable 1 or 2mm where they cross over, hence the feeling that it does it as you select gear. Just a thought!!


Paul
 

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The first thought that I had was sticking throttle cable too. I ride in all weather and the cable can get a bit gunked up even though the sheath is teflon coated.

Pull the throttle end off and give it some WD40 or the like and see if it has any affect. I did mine about a year ago when it was getting sticky.

It is a 10 minute job. :)

Good luck
 

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Discussion Starter #8
Sounds like a sticking throttle cable. Mine is doing the same thing (2K 955 ST)so I got a new cable, but have yet to fit it. The only other thing I can think is that there may be some movement from your clutch outer cable that is moving the throttle cable 1 or 2mm where they cross over, hence the feeling that it does it as you select gear. Just a thought!!


Paul
First thoughts that it was a sticking throttle but it isn't because the revs stay precisely at 2k and immediately drop back without touching the throttle when we dropped it into first gear. It's like a switch. Switch it on by putting the bike in first and geting revs anywhere over 2K, let the throttle off and it'll stay at 2K. Put the bike into neutral and it immediately drops to normal tickover. Rev the bike in neutral and it drops straight back to tickover.
 

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First thoughts that it was a sticking throttle but it isn't because the revs stay precisely at 2k and immediately drop back without touching the throttle when we dropped it into first gear.
Mine did this at a red light the other night; idled at 2k in neutral and dropped back to normal when I put it in 1st. Did not feel like it had a sticking cable and was exactly at 2k.
 

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Discussion Starter #10
Mine did this at a red light the other night; idled at 2k in neutral and dropped back to normal when I put it in 1st. Did not feel like it had a sticking cable and was exactly at 2k.
Sorry, my mistake. Mine should say 2K in first then drops to normal out of gear not in it...
 

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The 2000 Sprint, does it have carburators or injection?

I was thinking of other injection fueled cars and bikes I heard of that had a similar problem when the air intake sensor was broken and maybe this is something like that.
 

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Mine did this at a red light the other night; idled at 2k in neutral and dropped back to normal when I put it in 1st. Did not feel like it had a sticking cable and was exactly at 2k.
Hi,
mine is doing the same (still, I've written here about the problem some time ago, not solved it yet).
cheers
 

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CI & sajgon have you spoken to a dealer or mechanic about the issue yet? :)

As Lazarus Long has stated might be the AI sensor.
 

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Check your Throttle position sensor. Check your Idle Air Control motor......


When is the last time you had the throttle bodies balanced?
 

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Discussion Starter #15
Check your Throttle position sensor. Check your Idle Air Control motor......


When is the last time you had the throttle bodies balanced?
Will take a look at both as soon as I get the chance. Ill at present and Christmas coming up etc... Thanks for the advice though. :)
 

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Crazy if you do a search you can find out what proper voltage is at the TPS.

I can't remember off the top of my head so any number I put here will be suspect. I know I have posted it before and so has OnD so a quick search should bring it up.

As far as your IAC, make sure it is clean and not gummed up. Take it off and clean it up then replace it. They just tend to get gummed up with fuel and oil residue.
Good luck.
 
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