NSR Restriction

[UKRedwing]

So I've established theres no intake restriction tract plate and the exhaust looks like its allready been tampered with but I'm not sure, I don't even know what the exhaust restriction is on the NSR 2003 reg.
Pushing just over 80 mph max..
0-60 is pretty fast, I mean it's not 11 seconds like peopel say the restricted nsr is.

Anythign else that could be slowing my bike, its a UK spec so i doubt it has any CDI restricors etc..

[BenR]

https://www.125ccsportsbikes.com/forums/index.php?showtopic=17347


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Current bikes: suzuki RG125UN wolf. Yamaha MT-07

[UKRedwing]

Already have the document downloaded, no help with regards to the original exhaust

[buddy]

does it have restricted electronics?

check for the tv-78 cdi and ci626 powervalve controller unit thingy

sounds like your powervalve isnt opening fully



whats the frame number, ya can find it in the right side of the headstock
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When this baby hits 88 miles per hour... you're gonna see some serious shit.

[UKRedwing]

ZDCJC22C01....... Uk spec according to wikipedia.

[UKRedwing]

Heres a pic of the exhaust

It would be immensly helpful if someone with knowledge about it could direct me as to where in the exhaust the restriction is,
Then I can easily do it at home with all my proper monkey wrench etc tools.
https://i39.tinypic.com/vq47c0.jpg
Paint edit skills anyone?

[UKRedwing]

Bump.
So no-body knows where the restriction is O_o.. ?

[G]

Chill.

This should have what you need:
https://www.nsr125.com/derestrict.htm
It's at the manifold end, where the exhaust meets the engine.

[buddy]

the restriction is right near the exhaust port, the only proper way to check is to take the exhaust right off and have a look inside

actually, here is a website that will help ya https://www.nsr125.com/derestrict.htm

also have ya upjetted it yet? ya will need a 42 idle, 65 power and a 138 or a 140 main

140 is probably better performance wise
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When this baby hits 88 miles per hour... you're gonna see some serious shit.

[UKRedwing]

I r blind.

[G]

[Mr.Ormes]

the restriction should be right at the end of the expansion chamber/manifold, where the exhaust meets the barrel, there should be a copper washer or cone, or something which restricts gas flow there, simply drill/cut/grind/dremmel it out and you are de restricted!!!
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DT 125 1995
Thumpstar 120
Suzuki ZR 50

[UKRedwing]

Gonna sort it tomorrow then.
Anyone know how much a compression check test should cost? Gonne see if its above 130 pounds per square inch

[UKRedwing]

Took exhaust off today, no restriction atall. Im stumped now theres no other restrictions on the uk 03 spec which my bike is.. so I don't get why it only reaches 80 mph flat out

[G]

First off, can you confirm that you are red-lining it in each gear, throttle held wide-open when accelerating?

Next, I'd be tempted to whip the head off and see how the piston/cylinder looks. They can start to lose a bit of go as it gets near rebuild time.

[UKRedwing]

Yes mate, raches redline in every gear effortlessly except for 5th, if you try to take it into 6th it will just slow down.

I'm not mechanically competent atall so I have no idea what I should be looking at engine wise for wear, but the bikes done 13,200 miles so its nowhere near rebuild time, might need some piston rings though, have put 2k miles on it since I bought it.

Hopefully I can get compression checked in the engine and the tires, and grease the tire bearing see that they spins freely, plus a new chain and maybe a different sprocket set up. Don't know when gear box oil was last changed either so will check that.

Does anyone know where the CDI "box" thing is? I don't actually know what this is but I heard it might be the restricted version.

Cheers.

[salty21]

[UKRedwing]

Oh yeah Im trying it, not sure if the jets are allready at that though as the bikes fully derestricted prior to me owning it. The jets are on there way, they wont make that much difference tho right? between 80 mph flat out and 110 mph O_o

checked CDI its the fully derestricted one =/

should i cut a hole in my airbox and coved that hole in mesh for better airflow? would I need to upjet AGAIn ?

[G]

[UKRedwing]

Okie doke, well its pay day soon so Im going to get a mechanic to fit these jets when they arive, use a paddock stand or something (i dont have one) so cant really check whether wheels are spinning freely, new chain n sprockets, new piston rings. Might sort things out.

[stirlinggaz]

hi,
changing the jets takes 10 minutes.
(takes longer to get at the carb), can sometimes get away with not even removing the carb, just loosen off the 2 hose clamps & turn the carb upside down.
though probably better taking it off & giving it a clean while your there.
theres a very good guide to carbs from our resident 2t guru, Kickstart, on this very forum.
buy yourself a compression tester, should cost £18 for the basic one up to £40 for a kit with a few adaptors.
then you can test the compression yourself.
then if you need to do anything, there a good guideto doing top end re-builds, floating around, i'll post a link if you need it.
why pay someone to do something you could probably do yourself?
cheers,
GAZ

[UKRedwing]

Cheers, yeah i could probably so it myself but my airbos is sucha fcuker to get back on poperly over the carb i'de rather them take 5 mins to do it. Cash is a little hosrt atm so i can't afford to go out and start buying PSI equipments and stuff.

Whenever im not revving or idling and the bike is slowing down, I don't know if its cus im paranoid or i have started paying attention to my bike but is a has a sort of throuty "gurgle" as it slows down, not sure if this is normal, airbox and everything is on properly.
Any ideas?

[buddy]

hey mate

i had a similar problem to you, upjetting made abit of a difference and so did an irridium plug

before both of these my top speed was 85 and is now about 95



also be aware, i will take a very very long time to actually get to 95mph(well its prob not that long but it seems ages)
and ya have to get right down on the tank

my bike has done 24,000 miles aswell
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When this baby hits 88 miles per hour... you're gonna see some serious shit.

[Dilusi]

What sprockets are you running? I had a simular issue with my old MTX125, could hardly use 6th as it was geared too high. I replaced the chain and sprockets with standard items and it flew through the gears and would top out (eventually) in 6th. Used to see 90-95 on the clock which I thought was pretty good for a trails bike.

[Blau Zedong]

https://i5.photobucket.com/albums/y164/BLUEX5/facepalm.jpg
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18:54:48 Rob Fzs: jews don't give away stuff for free

18:54:59 Rob Fzs: unless its their clothes/ hair/ golden teeth