Trouble at 7k revs in second gear on NSR125

[GhostRider]

Afternoon,

Ok, so I've noticed that when firing along if I want to pick up speed I'll get to about 5-6k revs in 1st, then shift up to second.... but when I go into second, as I get up to 7k revs the bike seems to... well, struggle, stutter a tad, if I shift up to third then it disappears and I can go into high revs in all subsequent gears no problem, it just seems that in second it doesnt like being taken that high....whereas I was under the impression that she should be happy to keep goin until the red begins to approach...

Any ideas anybody? Wondering if I might be doing my engine no favours..??

Thanks in advance,

GhostRider
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I have all the characteristics of a human being: blood, flesh, skin, hair; but not a single, clear, identifiable emotion, except for greed and disgust. Something horrible is happening inside of me and I don't know why. My nightly bloodlust has overflown into my days. I feel lethal, on the verge of frenzy. I think my mask of sanity is about to slip.

[Timmeh]

Does the bike judder in second?
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GSXR400 x2 | '94 RVF400 | '93 TZR125 4DL (again)
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[GhostRider]

[djrichieb]

If it only judders upto from around 7k i would say its either a fueling problem (sounds unlikely since you say its ok in other gears) or the powervalve possibly? Does the powervalve move and whats the top speed at the min?
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Rides: Honda CB400 SF (ART can) - Citroen Saxo 1.1i SX

[Vincent]

If it's only doing it in 2nd gear, I would have thought it's a gearbox problem

[floodtube1]

[L3G3ND_MTX]

Had this problem on my rs125 for a little while, it might be that your cracking open the throttle to much in the lower gears (opening the throttle right up) try just using half of the throttle, i had the exact same problem and mine was fine in higher gears aswell i found out me opening up the throttle to quickly was flooding it some-how

Hope this helps you.

P.S. no it wasnt the enviromental dip that i was having because mine was between 7-8k revs and i dont have a power-valve as there is a blanking space because its new and restricted just thaught id say incase people say.

Good Luck!

[alains]

does it do that after 10 min warming ?
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the worst day fishing is better than the best day working

[GhostRider]

Ok for some reason it doesnt appear to be doing it anymore......at least not the last few times I've been on it...though I'll be keeping an eye on it.

For future reference though, yes it will rev to 7k in neutral no probs.

Im not sure how to check the powervalve, top speed I've got so far is 60mph, though it does seem to take its time getting up there, but then again not many roads long enough around the routes I drive to warrant doing that speed or going any faster...

And yes it appeared to do it after the bike was more than adequately warmed up.

As I say problem seems to have disappeared for now but will keep a close check on it.

Thanks for the responses guys,

GhostRider
____________________
I have all the characteristics of a human being: blood, flesh, skin, hair; but not a single, clear, identifiable emotion, except for greed and disgust. Something horrible is happening inside of me and I don't know why. My nightly bloodlust has overflown into my days. I feel lethal, on the verge of frenzy. I think my mask of sanity is about to slip.

[alains]

you must do at least inspection of all connections on CDI,RC/unit,servo-motor , oyde is your enemy
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the worst day fishing is better than the best day working

[djrichieb]

A top speed of 60/70 sounds like your powervalve is not working. Does the bike make a noise when your key is turned, like a wooring noise for about a 1 second?

If you sit on the bike and look under the right side of your petrol tank you will see a small round silver object sitting on a plate with two small cables coming off. This should spin depending on what rev's the bike is at (in neutral or in gear) and there is a little pointer on it that points to hi or lo. If this doesnt move get the serial number from inbetween your yokes (just below the handle bars) and give it to alains. Your bike could be restricted so the power valve can not work.
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Rides: Honda CB400 SF (ART can) - Citroen Saxo 1.1i SX

[GhostRider]

[alains]

your valves are ok , they will go to HI over 7500
prior having top-end re-build go to your mechanic and have your compression tested something lower than 100 psi is not very good
____________________
the worst day fishing is better than the best day working