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Discussion Starter · #1 ·
Hi, ive recently bought an aprilia sx 125 and im wondering how i de restrict it? does some one know a guide or could someone tell me what and how to derestrict it?
It feels like its restricted in de CDI because it feels like i cant rev it out like i should be able to, Ive got a Rave but however im not certain if it works, at what rpm should it move? and how do i check? The aprilia has gone 500 swedish miles so i might have to clean it up?
Also might need to change the chain etc. whats the best gearing setup? ( i know im asking quite alot but hopefully someone can answer atleast some of the questions).
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Discussion Starter · #3 ·
as far as i know theres load of enviromental "friendly" sh*t in this one and ive heard its quite hard to derestrict, ive also got a 02 rs but it doesnt look anything like that but ill check if theres an 07+ rs guide
 

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Im not sure on the cdi take a pic and lets see it but the others are a cat in the exhaust a powervalve set up and ur spark plug will need changing n rejet ur carb o and open the blocked off snorkel on ur air box Apart frm ur cdi cus i dnt no its not very hard
 

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Discussion Starter · #5 ·
ive got a powervalve, however im not certain that it actually works, I should probably clean it up and make sure its not stuck.
Ive heard that the carburetor is connected to the cdi and restricts the engine from revving as high as you would want it to be.
The airbox snorkel is gone and rejeted, i think ill try to get a new exhaust from either an mx or some giannelli/arrow one.
However the cdi is really the biggest problem.
Also im going to get a new chain and sprockets, which gearing is the "best"? right now i use it to drive quite far and not just short funny trips :p.
Thanks
 

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Discussion Starter · #6 ·
ive got a powervalve, however im not certain that it actually works, I should probably clean it up and make sure its not stuck.
Ive heard that the carburetor is connected to the cdi and restricts the engine from revving as high as you would want it to be.
The airbox snorkel is gone and rejeted, i think ill try to get a new exhaust from either an mx or some giannelli/arrow one.
However the cdi is really the biggest problem.
Also im going to get a new chain and sprockets, which gearing is the "best"? right now i use it to drive quite far and not just short funny trips :p.
Thanks
 

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Discussion Starter · #7 ·

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Hey fractal you are correct with the hole in CDI
To check the rave controller rev the bike above 8000rpm and rave solenoid should shut very quickly and stay shut until below 8000rpm you will also hear a change in exhaust sound.
Follow this guide --- http://tuul.tl//10722551.pdf --- for derestricting aprilia rs euro 3 model this works very well for sx125 and make a big difference over stock bike but decatted exhaust needs to be fitted at the same time to be effective

That black thing above carb is TPI, Throttle Position Indicator I am unsure what this controls but bike will run fine with it disconnected, I think it may control the air solenoid which can be seen in your picture of carb top http://imageshack.us/photo/my-images/593/20120607113514.jpg The brass looking piece to the right hand side of picture.
 

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There is pretty good YouTube clip showing all the steps to destrict. The RS and SM use the same engine so same procedure and all steps need to be done, missing a bit could leave u with problems:
1) rave valve installed (biggest change) replaces the static exhaust valve with a variable one. You need the solenoid and cable bits as well as this opens the exhaust valve at higher runs.
2) drill the cdi box; freaky but aprilia race experts planned for this. This allows revs to be raised, and valve opening to happen
3) remove air box snorkels; your engine is going to need more air
4) new carb jets, cause your engine is going to want more fuel
5) get rid of standard exhaust and cat; those exhaust fumes need to escape more quickly
6) upgrade your spark plug to one that can cope with higher reving

I think I covered all points. But major warning I would give is, do everything at the same time as missing any of these steps could seriously damage your engine. Also know, you are trading performance for engine longevity. Older engines might not like these changes and you could damage your bike
Also, test your changes and make sure everything is working as it should, ideally a professional with a dynamic should be employed.
With that in mind, I have no idea what the impact is on the 125cc engine, 15bhp to I dunno.
Best investment of your time and money, upgrade your licence and get a bigger bike!!!
 
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