The Aprilia RS125 comes with a CDI restriction. It retards ignition around 6000rpm so the bike can pass EU emission tests so they can be manufactured. This makes your bike perform very poor at 6000rpm and does not let the engine pull. Derestricting this will invalidate your warranty. If you bike is in warranty the best thing to do is buy another CDI and derestrict this and use it on your bike.
Derestricting the CDI?The CDI is a black box under the passenger seat. Therefore to get to it you will need to remove the tail of the bike. The easiest way to do this is to remove the rear side fairings with the tail. See the manual for more details.
The CDI will have a serial number on it? if the serial number is in the following format 071000-XXXX-XXXXX then this derestriction will work if done correctly (may still work on others).
You will need to cut out a hole in the CDI to reach the bridge. Cut out a rectangle 30mm by 10mm and 5-10mm deep.
You will see a part of a circuit board, snap this. This is known as the bridge. (If you reach glass it means you have dug too far!)
Once you have snapped the bridge, fill your hole back in with silicone, make sure its waterproof! Now there will be no environmental dip between 5000-6000rpm.
Here is a detailed diagram...
Full Power Derestriction
The Aprilia RS125 can be restricted so its learner legal, and then derestricted to full power (claimed 33bhp). To do this you will need the following items:
o RAVE controller
o Powervalve blade
If your RS125 is restricted then it will not get a significant power increase around 8000rpm. If you know the powervalve is installed but you are still not getting this increase ensure all parts are working correctly, connected, and the solenoid is set correctly.
What does the powervalve do?
The blade of powervalve goes in the barrel of the engine. This then moves up and down to increase and decrease the exhaust outlet size to give you different performances at different rev ranges. The more revs you give the bike the more the powervalve blade is pulled by the solenoid and opens the exhaust outlet.
All a solenoid is, is an electromagnetic componet. Bbasically all you need to know is it pulls a cable which is connected to the powervalve blade to pull it out to increase the gap in the exhaust outlet.
You must check your bike for the componets listed above.
Your bike may be restricted via a blanking plate. You can see this by removing your right side fairing and looking above the exhaust. It will be a small plate and have 3 bolts along it (one either side and one in the middle). If you see a blanking plate then you will need to purchase the powervalve blade, mount, and other parts see parts diagram below... Your probably best getting a gasket for it too even though there is one on the blanking plate... you can reuse them but to ensure the bike performs well and you dont get any problems get a new one...
Once you have aquired these parts remove your blanking plate and fit the powervalve into the bike.
Note, the powervalve goes in one way!
It has a tapered end on one side, this should face downwards, and the flat side of the powervalve blade should face upwards! Ensure you do this!
If you can see the powervalve mount sticking out the exhaust then you will not need to purchase it of course and you will see something like this above the exhaust...
Remove your tank...
To the right of the battery there should be a solenoid which should have a cable connected on the end of it. The cable connects to the powervalve blade that goes into the engine that we looked at before.
It should look something like this altogether...
If you do not see the solenoid and/or cable then you will need to purchase these.
Once you have purchase these parts mount them to the right of the battery, there is a place for it to be fitted, it goes on the part of the radiator frame that goes right next to the battery.
If you see the solenoid and cable, and you see the powervalve mounted in the engine but your bike is not performing as it should... then it may be a case that the solenoid is not connected! If you look on the picture above there is a connector block on the end of the solenoid, see if this is connected, it connects to the main loom which runs along the right hand side of the bike from the front all the way to the back of the bike.
If you connect it up and it does nothing then keep reading....
Remove the passenger seat and check for the RAVE unit. (just remove the two back side fairings and tail)
If you cannot see this, then you will need to buy one of these and fit it to your bike. There will be a spare connector block coming out of the main loom were it should be connected to. Once you have fitted all these parts your bike should be derestricted!!!
All you need to do now is to set your solenoid up correctly... It has adjuster nuts on it, so the cable can be adjusted. This is because the solenoid starts acting around 3000rpm (you can see the solenoid opening when you rev the bike to this with the tank off). The more the powervalve blade sits in the exhuast the better low range power you will have, but poor top end. This works vise versa. See how to adjust your solenoid below...
WARNING: WHEN YOU DERESTRICT YOUR BIKE YOU WILL NEED TO CHANGE YOUR SPARK PLUG OTHERWISE YOU WILL BLOW A HOLE IN YOUR PISTON. Despite what the manual says, the spark plug to use when your bike is full power (powervalve installed) is a BR10EG. This is because the plug is colder. When your bike is restricted you should run a BR8EG. You can change these plugs for other versions e.g. Denso plugs, Iridium plugs for smoother running.
The later bikes 2003 onwards have a CAT in the expansion chamber. In the expansion chamber not the end can. To get rid of this CAT which makes your bike perform differently, get an after market expansion chamber (best buying the end can with it) or buy an earlier expasion chamber from an RS125 or take the expansion chamber off and be prepared to cut it open, remove the CAT and weld it back together.
If you are going to buy a different expasion chamber then you will have to rejet your carb. The bikes with a CAT in them are set to run rich (more oil) because the CAT requires the bike to run like this. Therefore you will need to buy a standard main jet for your carb. If you have a 28mm carb (finally got it right I normally say 26mm) then your standard main jet size is a 120. If your carb is a 34mm your main jet is more likely to be a 158(i think) You can get these for a couple of quid. This means taking your carb off and removing the old main jet, and replacing it with a new one.
The racers tend to use the standard expasion chamber because it is thicker then aftermarket ones therefore contains the heat more, and these work better with more heat. They normally just change the end can.
Removing your CAT (if your being a big man)
You will need to take your expasion chamber off the bike (see manual if you dont know how)
You need to cut your expansion chamber open where this fella is cutting it and where the white
Once you have done this you will be able to remove the CAT
Thats it really, dont know too much about it because I havent done it... Just weld your expasion chamber back up with the CAT removed, give it a respay (heat resistant of course) because they tend to rust like hell even if you dont ride your bike in the wet.
The expasion chamber doesnt really have anything in it anyway if your thinking this was too simple. Literally just cut it open, remove the CAT and weld it back together.
Some exhausts also have a recirculation tube that goes to the air box. You just have to cut this off and weld it up and seal up the air box.
The snorkel in the air box can be taken out too, this will let some more air in slightly and make your bike sound a lot better. Just pull the rubber out the top, or you can cut the part that sticks out. This shouldnt affect your jetting since the bike is not jetted correctly from standard anyways. If you want to be sure stick a bigger main jet in (121 on a 28mm carb). Do a plug chop to confirm. To do a plug chop see the pinned topics... under useful RS125 information.
The older bikes had a 34mm carb on. The new ones have a 28mm carb. I think it was the 98's that had the 34mm carb on then after that unless modified it was a 28mm carb. If you want better mid range power, and a better top end without affecting your petrol consumption too much get a 34mm carb. The petrol consumption is suprisingly good, it does guzzle more but you get that back in power!
All you have to do is get hold of a Deloroto VHSB 34MM and a new inlet manifold because the original will be to small and then fit it onto your bike. The standard air filter will still fit this new carb.
Well thats basically it. Your bike is derestricted...
How To's Number 1 - Air Filters Cleaning
The procedure for removing, cleaning and reffiting of standard foam type RS filters is fairly standard for the RS50, RS125 and I imagine the RS250 too.
Put the bike on the stand. Remove the Petrol Tank, on the 125's the tank hinges once the 5mm socket type allen bolt is removed from the front of the tank. On the older 50's (pre '99) there are two bolts one at the front of the tank and one under the riders seat. I don't know how the newer 50's tanks come off - I am sure you will. DONT FORGET TO TURN THE FUEL OFF AND DISCONNECT THE FUEL LINE.
Remove the air box lid, the airbox is a black plastic box that contains the air filter. With the lid off you should be looking at a piece of foam (usually black). Remove this foam and beat any large dirt particles off it away from the carburettor air intake of course.
The foam is soaked in oil and can be re-oiled using a heavy oil. Some shops sell a special air filter oil, if not just use a 80w/90 gear oil or similar. Soak the foam in the oil and squeeze of the excess - be sure to leave the filter feeling damp to the touch.
Re-fit the foam and reverse the above procedure to reassemble the bike.
THIS WILL NOT GIVE A PERFORMANCE INCREASE
How To's Number 2 - Chains
A few pointers. Always adjust the chain at the tightest point , chains ( especially cheaper ones)will develop slacker and tighter 'spots' on them so you must rotate the wheel a few times to find the tightest . Leave it a little looser than you might think and then climb on and reach down to the chain . You should find that your weight on the bike tightens the chain (depending on your weight and how tight you have the rear suspension) If you tighten the chain too much it will be too tight when you get on , you should adjust it to have the correct slack when you are sat on it.
I don't know if they are all alike but mine needs 11mm and 10mm open ended spanners for the adjuster and lock-nut plus a 26mm socket for the axle-nut. A good investment is a paddock stand . I have no idea how you do any of this without one , but you have to get the back-wheel off the ground to make a proper job of it.
Don't slack the axle-nut completely off , you need a certain amount of friction to hold your adjustment .
Always make sure you turn both adjusters the same amount in or out (use a measure or some dividers to check )and make sure the axle is pushed in so the adjusters are tight up on the swing arm .
If , when you spin the wheel afterwards , you find that it won't spin freely , slack it off until it does.
If you can't get the correct adjustment (too many tight and slack spots or no adjustment left ) get another chain !
Personally I fitted an 'O' ring chain about 6 months ago and it has only needed adjusting once , just after fitting when it had settled down a bit. If you keep it well lubed and check it often ( every 250 miles or so, I do mine every fortnight ) a chain can last a long time.
Don't forget the sprockets . If they get worn so the teeth are no longer even (they will get a sort of curve on one side and go pointy or even have a 'hook' if they get really bad ) they'll destroy a chain in nothing flat so it is best to do the whole lot as a set .
If the sprockets are good there is no need . of course. Sprockets can often see off more than one chain. (bit like front tyres and back tyres ).
It is very important to keep the wheel in correct alignment with the adjusters as this will write-off both the chain and the sprockets if it happens , not to mention dumping you in a hedge !
If it starts to go out of alignment you can sometimes tell because the bike starts to prefer to go in a particular direction ( right handers will be good but lefties will feel unbalanced for instance , but don't get too excited 'cos duff steering head bearings can do that as well !)
If the axle-nut isn't tight enough the left side tends to slip BACK and you will see a gap between the adjuster and the swing arm. This is because the chain pulls on the right side, I think.
Don't forget , the adjusters work by pushing the axle backwards but if the axle-bolt isn't tight there is nothing to stop them going further back so be warned .
The thing to remember is that the chain has to have a bit of slack in it. Too tight is just as bad as too loose plus the chain will loosen itself by stretching which will destroy it . It isn't too bad with our little bikes 'cos we don't have the power of bigger bikes but on the other hand a badly adjusted chain will rob us of what little we have got ! A good quality 'O' ring chain , properly adjusted and lubed with good sprockets will last a long time on an RS so its worth a bit of time and effort looking after it.
just a couple more things to add. When you replace a chain its easier (this is if you are not replacing the sprockets) to attach the new one to the end of the old chain and then just pull the new one on by turning the back wheel. If you keep the old chain this will give you the same option if you need or want to remove the new chain for cleaning at a future date.
If you clean the chain fairly regularly (you can get spray cleaners or use paraffin ) before lubing it this will also help keep it in good condition for longer. The best lube is the wax stuff you can get now but a good tip is to put a bit of 80w gear oil on first , rub the excess off and then seal it with the wax spray . Leave it overnight to dry and it makes a real good job of it and you don't get loads of oil on your back tyre.
As geoff says, best option is to lube the chain with normal chain lube(as this will lube the o-rings properly) and then spray on a wax type spray to resist corrosion. Always clean the chain before lubing otherwise you will make a great paste for grinding as the grit sticks to the wax, parafin makes a good cleaner and its cheap.
How To's Number 3 - Figuring Out Whats Wrong When She Wont Start
This thread was inspired by craigy who ran up against this problem recently.
So its 9am you're about to leave for somewhere important and you bike wont start.
You think "Ive got fuel" (if you have. - if not this could be your problem). Its always worth actualy lifting the filler cap to visually check for fuel. Many people have had £5 of fuel leak out through a nick in a tube or due to a poor carb and this will evaporate over the course of a night.
Kill Switch - Check It Now. We've all done it before left it off, or had someone else fiddle with it unbeknown to you.
Obviosly your ignition is on; because your using the starter motor. One to watch out for on a bike with a kickstart - yes I've done that too.
Check The Exhaust for blockages. A friend of mine took his scooter back to the dealership. where they claimed to strip the engine down, before noticing a bottle cap on the exhaust.
If your still not firing by now, you are almost certainly going to need to buy one thing atleast before you are. However don't forget to give the bike plenty of chance to fire up. Don't just give the button a little second long tap and expect magic all the time. Check the choke position too.
Now I would say you need to start testing for a spark.
Get Yourself to a point where you can remove both the plug top and the plug from the engine. If like me you have numerous plugs laying about (AND YOU KNOW FOR CERTAIN THAT THEY ARE INTACT) it is often quicker to put one of them in, instead of taking yours out. Whip the plug top off and put the replacement plug into it. Now you must Earth the plug using either the threads or the electrode at the very bottom of the threads. You must get the plug somewhere so you can clearly see if it sparks, and yet it has a perfect contact with the Earth of the bike. I have yet to own a bike with all engine paint still intact so I usually just put the plug on the engine. You could use the frame, or better still battery negative - you're guarenteed an Earth there.
Don't forget the kill switch and ignition switch. You will get a jolt off a plug if you hold it so the spark can get you. Hold the bakalight at the top, or the plug top.
Is it sparking?
If yes, (and you aren't already using the original plug from the engine) take the original plug out and check that one. If it doesn't spark now, buy a new plug.
If no spark, (and you are using the original plug) buy a new plug.
If no spark, (and you are using a plug you know is good) you have problems.
Check all the wires are plugged into the Cdi unit. Inspect these wires for chaffing they may have been cut right through from chaffing on something else. Check the HT lead (the fat wire the spark plug top is on) is screwed into the coil/cdi unit tightly and that the plug top is screwed into the HT lead tightly.
just one thing to add.The starter relay is located just behind the radiator. It is positioned so that the all the wires connect upwards into the unit. This means that it is possible for one (or more) of them to fall out. The symptom is that the starter will not turn the bike over at all but you can bump start it.( If you don't know how to bump start a bike I might do a 'how to' on that if there is any interest) If the wires are all as they should be the relay gets to be suspect. Like all other electrical components , they don't last forever.Worth knowing I reckon, Oh and don't forget the fuses !
How To's Number 4 - Carb Needle adjustment
You may find that at some point during bike ownership that life seems to suck because engines are complex. This simple little adjustment can and has made all all the difference.
Take off the tank
Undo the two flathead screws that hold the top onto carb - and lift out the slide.
or unscrew the carb top and lift out slide if you are on the 34mm carb.
Now you have to disconnect the carb slide from the cable - do this by compressing the spring in your fingers and pushing the cable down into the slide. take a look at the slide firstly to familiarise yourself with the motion to unhook the slide from cable.
Becareful of spring flying off, As once the cable is free the slide is left in your hand. Put the slide upside down (needle pointing upward) and let the little shim drop into your hand - this is a small metal plate on which the spring applies pressure to keep the needle fully down. The needle assy will push out now. You will see a circlip in a groove on the needle - there will be 5 grooves if memory serves me.
If the clip is on the bottum groove you will defo need to upjet. If the clip is in the middle groove - as most are try moving it down to the next lower groove (lower as in toward the tapered end of the needle). Reassemble the slide and bike and try that.
You have just effectivly moved the needle up into the carb slide more so more fuel can squeeze past its tapered end.
If the bike is better but still not right move that clip down to the bottum groove and retry. If that is better still - but still not right then you will have to upjet - and it is usualy the standard to reset the needle to middle and jet from that standpoint.
If the above suggestions make the bike worse try moving the clip up a groove then two etc. Although it sounds as if your mix is too lean; two strokes are wierd things sometimes.
How To's Number 5 - Fitting Braided Lines
Its good practice when doing any major brake work to change the fluid anyway, so yes I would change it, if you had two identical rs's one with new fluid and one with 3 year old fluid, you may not notice a difference in stopping power, but there will be a difference in feel (and afterall feel is crucial to using brakes to maximum effect).
Lets say you have the front master cylinder (m/c) infront of you. You crack the banjo bolt loose and fluid trickles out, there will be fluid coming from the top of your brake line (only a bit obviosly as it is the highest point but it will dribble for a few seconds),fluid will also be dribbling from the m/c, this is the fluid which is on the 'outside' of the piston, once this is dried up no more fluid will flow from the resevoir (which is effectivly situated on the other side of the piston) until you pump the brake, a stream of fluid will be ejected.
If I was doing this job, I would start by bleeding the brake, in doing this you will practically empty the resevoir by continually taking fluid off from the caliper bleed nipple (best to do this with the caliper on and pads in).
Once the resevoir is empty stick a clean rag in it, this will soak up the dreggs of fluid and prevent dust getting down the pipe to the m/c piston.
Now I would carefully (remembering brake fluid is a good paint stripper) remove the lower banjo connection (on the caliper) once free clean up the fluid lost onto the caliper - the best mechanic on Earth will lose some drops.
Get a little jar or something and stick the (probably dripping, but hopefully not to quickly) free end of the brake line in the jar. Now crack the m/c banjo loose, air will flow in and the fluid will drain out, into the jar. Remove the banjo completly.
Clean the spilled fluid up and stick some rag into the threaded bit of the m/c (where you just took the banjo bolt out of).
Get that horrid rubber hose outta the way somewhere. But check the length of it against the braided in the box, (if i had £1 for every time we got the wrong cambelt in the garage I worked at) same length? Good.
Get the caliper off now and drop the pads out. Clean the caliper and all the related parts, if you wanted to be dead pro you could split the caliper into its two halves (I do this usually if Ive already gone to this much trouble - but it is by no means mandatory, as long as the slave pistons move freely in their pots the thing will be fine with a good clean.
Get the nice new banjo bolts from the box (there should be new ones because the fittings on braided hose aren't as deep as those on rubber, so shorter bolts may be needed - Ive just cut down the originals in the past, but it doesn't look as good as some nice shiny new ones to compliment the lines).
By the way there is still going to be fluid in the caliper, which will eject if a piston is moved, and will probably flow out if the caliper is upside down.
Doesn't Really matter which you re-connect first, just remember to route the line properly, re-connect both ends of your new line and tighten the banjo's to their final tensions (you should get some new copper washers too if the kit is half decent) the washers fit either side of the line collars (the end bits).
Armed with your new fluid, which you hopefully didn't shake up, thinking that it was wd40 (ahem ).
Fill the resevoir half full, and attempt to bleed the brakes via standard procedure (those bleeders are good here, ive never used one though).
You will be ages priming the dry line with fluid (back bleeding is always an option), if you seem to get no where fast, raise the caliper above the m/c you'll have to refit the pads and get something between them to simmulate the disk, an assistant (or piece of rope can hold the caliper). They might take ages to bleed, but they will. Keep an eye on that fluid level though and top up as required, as you get some pressure on the lever WAIT a bit longer and keep bleeding in the upright position before re-mounting the caliper on the fork leg, and continuing to bleed. In my experience there comes a point when you have had enough of cursing and pressing the lever, you decide that you have enough feel (and bite) all be it quite late in the levers travel, to go out, afterall how many times do you brake on the road, loads isnt it and its not so boring, go out for a bit and the lever will get firmer on each use, until its fine, now go back home and flush a few more measures of fluid through, and re top up. It goes spongy immediatly after you run off the pressurised fluid, but within 10 more presses the lever has its feel back. Repeat this riding, then bleeding until you are happy.
Very often it wont need re-bleeding after the first ride, but it might.
Much the same as above but without the hastle of loads of bleeding, generally the caliper can be left bolted in while bleeding.
All About 125 Powervalves
Rave II was the first generation of rotax power valve. Rave by the way stands for Rotax Automatically Variable Exhaust. The Rave II works pneumatically (by air). A drilling transfers some air from the exhaust port to a diaphragm which forms part of the pv assy. The valve blade is bolted to this rubber diaphragm, so when the exhaust gas pressure reaches a high enough level to overcome a tensioner spring acting on the back of the diaphragm, the diaphragm can inflate and in doing so it opens up the powervalve. The tensioner spring has an adjustable preload so that the rpm floor at which the spring tension is overcome can be adjusted, and hence the pv opening rpm.
The new powervalve is electronically operated by a solenoid aka. servo,motor, etc. The description Motor is incorrect, the device is a solenoid or servo this in esence a fairly powerful electro-magnet. When the servo coil is fed power it becomes a magnet which pull the iron centre in(which in turn pulls upon the cable). The new powervalve is called RAVE-E.
Rave-E and Rave II are equally likely to sieze in place. The ONLY sure way to make sure it doesn't sieze is make sure you ride with it open (a task most enjoyable). The main advantage of Rave II is that you don't need any electrical bits for it to work. Where as the RAVE-E needs an rpm sensor and control box to energize the electro-magnet coil. However the electronic type also has an advantage from a blade siezure point of view. It has a cycle at below 2500rpm where the valve is opened to assist keeping it clean.
On my rs I have the RAVE-E. It is possible to fit a RAVE II but you do have to remove a small plug from the air pressure transfer drilling.
CHECKING PV FUNCTIONING (CHEATS WAY)
One way to check the solenoid function is to put 12v accross the multiplug it connects with.
Find the solenoid and trace the two pieces of wire coming off it (electrical wire) not the pv cable. It will end in a two way multiplug which you need to pull apart, it will show two male spade clip terminals. To test it all you need to do is get two female spade clips on two pieces of wire (1.5mm square will do it), and attatch two crocodile clips to the other ends of the wire. One spade clip onto each of the spade terminals in the multiplug, one of those crocky clips on good live. The other crocky clip you can hold against the frame (making sure you have a good Earth) when you make contact with the frame it will open supply current to the solenoid. you will see it moving if all is ok. Don't worry there is no way you will get a jolt off this procedure. Its safe. Also it doesnt matter which way round the clips are connected. ie. either can be live or neutral.
How To De-restrict An Rs125
Rs125's have no restrictors in the exhaust unlike most bikes. To get 33bhp at the flywheel you need a powervalve, this is a valve that sits in the exhaust port and is opened electronically by a solenoid which is under the tank on the right of the bike - this is conected to the valve by a cable. The solenoid is contoled by a very basic EMU, which is at the back of the bike by the voltage regulator (under the pillion seat).you'll need this too most bikes already have it though.
You will pull like a train after 8000ish rpm if you have a powervalve. Also standard rs125 carb is a 28mm which is very restrictive the 34mm dellorto is the carb you need for full power if you fit this increase your oil pump's delivery to ensure you have sufficient lubrication.
Lots of people go for a gearing change too. Changing the front sprocket
to a smaller one will give better acceleration but reduced top speed and the opposite with a larger sprocket. Unless you need a new rear sprocket I wouldn't bother playing with that.
Lastly on newer rs's - on a rotax 122 engine (if it has a separate coil and cdi it is 122 if they are moulded into same unti its a 123) there is a spark retarder in the cdi box, there is a mod to fix this