[NSR 125] Adjusting the circuit for derestrictioning

[DimmniBurek]

Hi! I own a 99' NSR 125 and it is electronically derestricted (no restriction on carb, and it has restriction deeper in the exhaust(you must cut it))
I have derestricted the restriction deeper in the exhaust and I must say that acceleration really improved, but it still has no real power over 120-130km/h. Today I've tried the 2001 NSR fully opened with replaced jets, and the acceleration is way better! I did the circuit for the RC valves in the exhaust port, but I don't know how to adjust those two potentiometers! One is for timing of the valves to open, and one is to adjust the level of opening....
About the following potentiometer. Can it be adjusted to open too much? (I mean too much opened on low rpm)? How many ohms should it be?
How is with the other potentiometer? Does anybody know how many ohms open the valves on which rpm?


I was thinking of taking the RC valve out, if I won't be able to adjust this good. How will that affect the low rpm riding?


Another thing about that jets, alains, the slow jet [42] was today replaced on my friends bike, and on low rpm, the bike doesnt run well, it's like there is too much mixture in the barrel and so you must use the clutch and give a bit more throtle power to work good. When I ran it on high rpm the bike went good. Friend told me that before the change there was no problem....

On my NSR this problem also occurs, I would try to put the original slow jet back in
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[alains]

if your valves are correctly adjusted , you do not need to use the potentiometer , use the resistance . for the other potentiometer which times the opening do not set it too low (8500 rpm is correct) but you should use the resistance . i recommand JP1 on 1-2 , JP2 on 2-3 , JP3 on 2-3 , doing so , you do not need any adjustment . about your jets the main jet is effective between 2000 and 8500 rpm , the power jet over 8500 , the slow jet under 2000 . having fit the 42 you need to adjust the pilot screw (2 3/4 or 3 round undo) to fill a bit more air at idle . now normally choke on (in cool mornings) you bike should start at the first half round of the starter !
PS if you need the doc about the circuit , i think you've got my mail , ask for and i will send it to you
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the worst day fishing is better than the best day working

[DimmniBurek]

Hmm, I sure have every possible doc, you send me everything on my mail (you should remember-> [email protected])
How do I adjust the RC valves, I have that scaned doc about adjusting, but how do i get to that adjuster? Is there any oil in? I assume not!
Where is this pilot screw? I know there is one for adjusting the idle rpm!
The thing is: My friend has the main jet 140 and power jet 65, slow jet was 38 I think. And the bike was running good. Today I have changed only the slow jet and the bike DOES NOT run well! It has too much mixture under 6000-7000rpm!
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[alains]

ok , download my file https://www.geneva-racing.com/~alains/NSRtips.doc (1 Mo ) and this file https://www.geneva-racing.com/~alains/valves.doc (22 Ko)
in "NSRtips" you will find all the links for spares & docs (workshop manual, valves sequence) , in "valves" you will find the valves principles & debugging . the valves timming is clearly shown in the workshop manual to set them mechanically . you've got 2 adjusters : 1 is on the cable base guide (right side of the barrel) , the other one is on one cable . when you put the key on , the pulley goes on high as it will go after 6500 rpm until 7500 , now the circuit will give you an extra opening . i explain : the control unit has a reference value of the resistance mesured on the servo potentiometer and as this value is not reached the control unit will feed the servo in opening way , then if you put a resistance in // on the potentiometer , the resulting value is less , so it will force the control unit to continue feeding the servo .
hope you understand that and the circuit's resistances has been calculated to work at 8300 rpm et to open valves at maximum .
about you pilot screw , it's sited (if you look the carb by the right side) about 2" right of the idle screw , and it's normal setting is : full tightened then untighten 2 1/2 round so try between 2 3/4 to 3 rounds . an other thing , check if your clips on the throttle needle is set on the 2nd notch from the top .
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the worst day fishing is better than the best day working

[DimmniBurek]

Hey, I will try to turn that pilot screw and see how it works...
About that opening of the valves, I have read that docs you gave me! On the old NSR the valves opened fully at 5V, on the restricted ones they don't open fully(only 4V). So if I change only the TV unit for a TV-78, will it work properly, or do I have to change the RC valves also? I will try to adjust the valves if they are set wrong!
I have got a Gianeli exhaust and is thinner and lighter than the original one. Is it possible that the original one has any other restriction? Maybe deeper in the exhaust?(One was about 20cm in the pipe) I know that Aprilia 2001 RS 125 has whole shit in there!

You said that the valves open fully at about 8000rpm. When I was riding fully derestricted NSR it was gaining speed TO 8000rpm faster than mine! The acceleration was much better from 5000rpm than at my bike...

Is there any practical difference between the whole added circuit and only with that 2.7 kOhm restrictor? It has to be 2W, right?
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[alains]

if you change your rc valves unit by a TV-78 it will be perfect and you will not not anymore the circuit . no modification to do , just take off your TV-124 and put TV-78 . it will be very good also (if you change this unit) to change your CDI (which is the CI639) by a CI626 ,and before fitting it you must cross the green and the black/yellow on the 4 wires connector coming out of the loom (on the back left under your seat) . so after doing that you can have a look at my file "NSRtips.doc" the valves sequence is well explained .
about the genuine exhaust , yes it has an other restrictor but it's important to keep it , it eases the torque at low revs . the gianelli has cone and counter-cone calculated to avoid that kind of thing , but it will work perfectly with the TV-78 & CI626
did you fit carbon reeds , BR9EIX and jets 138,42,65 ? (sorry if i repeat but my memory is going down)
just in case , my file https://www.geneva-racing.com/~alains/NSRtips.doc
____________________
the worst day fishing is better than the best day working

[DimmniBurek]

It's OK, alains, I have bad memory too
I changed the jets for those which you recomended! I didn't changed the reeds, because I don't know if there is any advance. Do I gain acceleration or speed?
What if change only the TV unit? I'm kind of low on money....
So with Gianeli mounted I loose a bit of torque, but do I get more power at high rpm? Is the acceleration better? I don't care much about speed, but I need acceleration for going out of the corners and for overtaking!
I will buy a new spark plug, I would like to buy the best avaliable. In the manual it says it should be changed every 4000km, mine now it has 6000km, is there any possibility to crush and do some cuts in the barrel? Will better spark plug last longer?

You didn't answered on my question about the restrictor/circuit

alains, if we see sometime we should get a beer or something. i am very thankfull for your help!
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There Is No Stronger Drug Than Reality
There Is No Engine Like TURBO Engine

[alains]

on the genuine exhaust the other restrictor at the exit of the exhaust chamber just before the pipe going to the silencer. the reeds & sparkplug will improve the engine smmothness going up in the revs
the carbon will ease the mixture filling the carter-engine and they vibrate much better at high revs . the plug will give you a better repartition of the spark in the head and consequenty will give you a better ratio and save about 1/2 to 3/4 L on each full tank , also this plug a a longer like than the BR9ECS
about the choice between the potentiometer and the resistance it will provide the same result , with a little splutter around 4000 rpm until 5000 , but afterwards it's ok . keep an eye on ebay and if you see the TV-78 and the CI626 go for them
have a look here it's about £60
https://cgi.ebay.fr/Honda-NSR-125R-Italienische-CDI626-TV78-Top-Tunig_W0QQitemZ8028364969QQcategoryZ32109QQrdZ1QQcmdZViewItem
for your plug change it as soon as possible .
____________________
the worst day fishing is better than the best day working

[DimmniBurek]

Which spark plug do you recommend?
____________________
There Is No Stronger Drug Than Reality
There Is No Engine Like TURBO Engine

[alains]

BR9EIX cold weather & normal use
BR10EIX heavy use and summer days
____________________
the worst day fishing is better than the best day working

[DimmniBurek]

Hey, I have took a look at the alains tips...
About adjusting the RC valves... I have to get the cover off and those two cuts must be together? And thats it?

I wonder if I adjust it so that the valves will be more opened. Will it work as it is derestricted?

I have electronic restriction, yes
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[alains]

the point is to force the valves to open more . how ? adding something to make the pullet diameter a bit bigger or inserting something between the cable (the one which pull the valves) and it's sheath in the plastic stopper .
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the worst day fishing is better than the best day working

[DimmniBurek]

But do I loose much on torque?
That two cuts must be together? When nothing is changed or tuned?
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There Is No Stronger Drug Than Reality
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[alains]

what are thinking when you said these 2 cuts ?
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the worst day fishing is better than the best day working

[DimmniBurek]

Res ones
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There Is No Stronger Drug Than Reality
There Is No Engine Like TURBO Engine

[alains]

ok it's the notches . just tell me where is sited the cable with the spring , left or right (on the barrel) ?
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the worst day fishing is better than the best day working

[DimmniBurek]

I'm preety sure on the right looking from up(under the tank)
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There Is No Stronger Drug Than Reality
There Is No Engine Like TURBO Engine

[alains]

ok , use your adjuster and tighten the cable as max as possible . put contact on and see if it's any more play between the sheath and the stopper near the servo pulley .
____________________
the worst day fishing is better than the best day working