NEED HELP ASAP NSR125:(

[sunbear]

Need some help as soon as poss! Today hopefully My NSR125 was holding back on revs between 6-7000 rpm before the power kicked in. I was told by that Stan Stephens fella to lower the pin one notch in the carb. After doing this the engine is now really badly spluttering at around 5000rpm and revs wont go any higher. I changed the needle back to its first position to see if this was the problem (2nd notch) but its doing the exact same thing. What have I done????????? HELPPPPPPPPP !!!!!!!!!!

[NC30UK]

Check your mixture settings.

[fuzz]

https://www.factorypro.com/tech/carbtune,CV,high_rpm_engines.html

I wouldn't suggest you try all the methods on the link, but have a look at the section on midrange. It should help you figure out where the needle should be.
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Bikes: '99 NSR125R, '00 SV650S, K1 GSX-R600, '97 CB500, K3 SV1000S, '16 VFR800

[sunbear]

But the bike didnt do this with the notch set at 2. After i set it back to 2 it was still doing it ?

[fuzz]

Are you sure you haven't moved the mixture screw?
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Bikes: '99 NSR125R, '00 SV650S, K1 GSX-R600, '97 CB500, K3 SV1000S, '16 VFR800

[sunbear]

Yeah deffo, only thing i did was remove needle and put it back

[sunbear]

Oh I forgot to say, when i first moved the needle the bike ran fine for about ten minutes before this spluttering business started . PLEASE HELPPPPPPPPPPP

[Rob W]

I know this doesn't really help, but that sounds like what my ZXR did after I got knocked off.

Before the crash it was fine, ran perfectly, then after I got knocked off, between 4-6Krpm it would splutter and struggle to get through that rev range, but above and below that it was fine. I had the carbs off more times than I can remember and checked everything on them, and there was NOTHING wrong with them. Seriously, there was nothing I could spot that would cause it to do what it was doing. I set everything back to standard settings and it still ran the same.

In the end I had to get a new set of carbs off eBay and that sorted the problem. My old carbs are still in the garage and I still have no idea what caused it to do this. Like I said, not very helpful, .
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TS50 > Senda 125 > ZXR400 > CB-1 > GSX-R1000 > Bandit 600 > ZXR750 H1 > GSX-R750 SRAD > '98 Fireblade > T595 Daytona > Hornet 900 > '04 Fireblade > GSX-S1000F (x2) > '23 XSR900

[sunbear]

Ok . No carbs on eabay for a '9 nsr125 Where else can i get one ? In the mean time, any more ideas about the problem ?

[WavyGravy]

As the only thing youve touched is the carb, then the problem is with the carb.

Is it possible youve bent the needle? ... they are precision components and the smallest imperfection can cause your symptoms


You might have got dirt in the carb while it was open, the smallest flake of paint/ bit of grit / fluff / etc can partially block a jet, cure is to remove carb, take it to bits and blow compresed air through every little hole you can find...... no compressed air then use an aerosol carb cleaner, use it in every hole, the longer you look the more holes you'll find!


hope this helps
____________________
1975 CB125s, 1991 GN250, 1990 Ducati Paso 906
"Don't wake him up - He's got insomnia - He's trying to sleep it off"

[Handsome]

Have a look on Bikersyardsalvage.com for a Carb.

HTH.
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Previous Bikes...Honda NSR 125 RR...Kawasaki Zephyr 550...Suzuki SV 1000 S...Yamaha FZ8...Current Bike...Suzuki GSX-R 750...

[alains]

in case you've got problem to find it , i've got one almost new with the venturi at 30 . pm me
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the worst day fishing is better than the best day working

[sunbear]

thanks for all that guys keep it coming if anyone has anymore ideas

[fuzz]

Which groove did you put the clip in? Did you go from 2 to 1, or 2 to 3? 3 is standard, so I think if you put it in 1 you were running lean. Are you sure Stan Stephens told you to lower the needle? I would have thought he meant lower the clip to raise the needle slightly higher out of the jet, and richen up the mixture.
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https://www.bikepics.com/members/fuzzbcf/
Bikes: '99 NSR125R, '00 SV650S, K1 GSX-R600, '97 CB500, K3 SV1000S, '16 VFR800

[sunbear]

Yeah he told me to lower the clip. So I moved it from 2 to 3 . But the engine started spluttering at around 4000rpm . So I changed it back to 2 and its still doing it Was funny on the way to work this morning . The bike will only rev to about 5000rpm and i had a trail of disgruntled car drivers behind me

[sunbear]

Just for information, once the bike eventually gets past 5-6000rpm its fine till it hits about 9000rpm then splutters again ? PLEASE HELP MEEEEEEEEEEEEEEEEEEE

[fuzz]

Might be a silly question, but have you warmed the engine up properly before trying to push it past 5000?
____________________
https://www.bikepics.com/members/fuzzbcf/
Bikes: '99 NSR125R, '00 SV650S, K1 GSX-R600, '97 CB500, K3 SV1000S, '16 VFR800

[sunbear]

Yeah and it was a silly question

[sunbear]

lol

[WavyGravy]

assuming youve tried everything so far it can only be the fuel tap, does it have a mesh filter in it? ive had it where a bike would run fine while the fuel wasnt being heavily drawn on but increasing revs would quickly drain the float bowl in the carb causing fuel starvation, turned out to be a mesh in the fuel tap had acumulated some crud, also if it is fuel starvation is the fuel pipe being nipped? or got a bend in it?
____________________
1975 CB125s, 1991 GN250, 1990 Ducati Paso 906
"Don't wake him up - He's got insomnia - He's trying to sleep it off"

[NSR-Rulez]

The NSR's do slow down between 5-7000 revs as the powervalve is not open, so it will take a while for the power to kick in, but there should be no reason for it to splutter over 9000, it really does sound like it hasn't been warmed up properly, i spend about 5-10 minutes warming it above the blue bar, then i ride gently for a mile or two to get the needle into the white section, then you can ride it past 9000rpm.

Is yours derestricted?

Hope this helps


NSR-Rulez
____________________
Past: 1985 Suzuki GS 125 + 2002 Honda NSR 125 R-2 + Ford Fusion
Present: Honda CBR 600 RR-5 + Suzuki SV650S-K4 + Mitsubishi FTO GPX

[swampy]

Have you put the carb back in its rubbers between the air box and carb, and between the carb and reed valves properly ? I've taken the carb out before to have the bike running like shite, only to find I was leaking air like a sieve. Worth double checking, cos it is really easy to think that you have done it properly. You could also try spraying some WD40 around the rubber manifolds, if the engine revs rise then there is a leak somewhere. My guess would be that you may have failed to put the air box on properly, rather than not attached the carb to the inlet manifold.
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"I hate to advocate drugs, alcohol, violence or insanity to anyone, but they've always worked for me." Hunter S Thompson
"Faster, faster, faster, until the thrill of speed overcomes the fear of death..." Hunter S Thompson

[yaut]

[sunbear]

Cheers for all that will try what i can tonight Anything else?

[sunbear]

What would cause problems if all i did was change the needle position, it didnt work so i changed it back, and now still doesnt work? Had a bit of trouble getting the airbox back on properly. Didnt remove the whole carb from the bike, just removed the top to get at the needle Really stumped. Im off work tomorrow if anyone lives close and would care to take a look (birmingham).