2003 Aprilia RS125


Fragile like a baby, but fun like making a baby


Engine blown after 5000km.

Engine blown again at 10000 km.

Water pipe burst.

Went through six spark plugs in the first 1000km.

Cooling system blockage.

Temperature sensor failed.

Power valve broke.

Chain flew off under acceleration once. Luckily it went away from the wheel!

Went through a lot of rear light bulbs.

General Comments:

I did my CBT as a stop gap, as I was short of money and couldn't afford to take driving lessons and buy a car. I bought an old "Y" plate Yamaha SR125 for £150 that was a complete shed, just to get me started. I didn't think that the "Biker Bug" would get me on such a machine, as I have always been car mad. But the bug did get me, and I decided to go the whole hog.

I bought a copy of Bike Trader and scanned the ads. I was torn between the Yamaha DT125 and Honda NSR125 due to their reliability, but I made the mistake of visiting my local bike shop, where on display was a new Aprilia RS125. Of course, a couple of my mates had had them, but I was warned that the bikes were seriously unreliable and troublesome. Anyway, I managed to talk the guy at the bike shop into letting me have a go, and I was in love. I went straight home and found a good deal on a bike.

The bike was a UK spec 2002 SBK replica, pre registered on an "03" plate, with lock, one years insurance, helmet, jacket, gloves and free CBT. As I already had my CBT, I talked them into delivering the bike for free instead (the bike was coming from Oxford, I live in Tamworth). The bike was dropped off that weekend with a grand total of 6km on the odometer.

Now, on with the review.

Some of you may be looking up at my list of problems, which may look pretty bad, and thinking that maybe that pretty Italian mini sports bike is not for you after all, but I do have to point out that most of them were my fault.

The spark-plug problem was sorted out after many return trips to my local bike shop, and it turned out that the bike had been fitted with an inferior spark plug at the factory by mistake. The bike would run fine for about 50km, then there would simply be no spark or ignition. I think that it was on the fifth trip back to the store that someone looked at the instruction manual for the bike and realised the problem. I immediately found another shop to work on the bike! You may mock me for not realising myself, but I'm not really mechanically minded, and didn't want to take a spanner to the bike myself in fear of creating even more problems.

I ran the bike in properly, which meant not going over 6000rpm for 500km and a top speed of 55mph and snail-like acceleration. Very frustrating, but it has to be done. I got the first service done at my new shop, a shop which specialised in Italian 125's for a grand total of £50. Bargain. I was now told that I could open her up and start having some fun. Yahoo!

The next day, I gently warmed her up to 70 degrees, as instructed by so many people, and then wound her right up. The bike flew round to 8000rpm... then nothing. D'oh! I took it back home, and thought to myself that I would take it back up to the shop the next day. I never got round to it as I found the problem the next day. In the morning a nice bloke came from Carole Nash and dismantled my bike to fit a Thatcham Cat 1 immobiliser, and found that the shop I bought the bike from had disconnected the electronic powervalve to restrict the bike. So, we hooked it back up, the nice bloke put my bike back together and off I went.

Warmed up to the dictated 70 degrees and opened it up. And the thing just took off. It flew through the gears in a flash and I realised that I was storming down the road at an indicated 110mph, which is pretty damn quick when you've spent around 8 months on two bikes that wouldn't go past 60! I was hooked on the power. As a result, once the bike was warmed up, I redlined the bike everywhere. The bike stood up well and I began to think that everyone was having me on about the reliability issues.

As I came up to the 5000km mark, I booked the bike in for the warranty required piston-ring change. I had the parts and everything. The the day before it was due in, I came down a local road and the engine stalled. I thought that I had ran out of fuel, so I flipped it over to reserve, opened the throttle to prime the carb and hit the starter button. I was rewarded with a very loud bang and a huge flame from the exhaust and was left sat it a cloud of smoke. All from a three month old bike. Whatever I had done, I had done it properly.

Turns out that due to my "spirited" riding style, I had worn the piston rings right down and the piston had driven itself through the cylinder wall. I had mullered every bit of the engine apart from the casing, carb and exhaust. The shop collected the bike and presented me with a £400 bill. Whoops.

While the bike was in, I requested that some additional mods were made. I had a carbon performance exhaust fitted, a performance filter and induction kit fitted, a performance carb fitted and some other jiggery pokery done to the internals and powervalve. Before the work, the guys at the shop had it on their rollers and told me the bike was 33bhp standard. After my work and the running in of the (many) new components, I had around 39bhp. This may not sound much, but it was. I could now top out at 120-125 and 0-60 was phenomenal. At one stage I had a stoplight challenge with a standard Impreza Turbo and I was nosing ahead. I completely destroyed my wife's V6 Ford Probe.

But due to all of my finniking, and a new job 30 miles from home, the engine blew again, so I had it put back to standard. After nearly a year of riding in all weathers, little things like the chain coming off due to it not being tightened properly, and sensors blowing and pipes bursting, I decided to cut my losses, take my driving test and get a car. Which I did.

But I miss the bike. The thing was incredibly uncomfortable, noisy, harsh and expensive (would only run on Super unleaded, £15 for a bottle of 2-stroke oil, tyre prices the same as my mates Ducati Monster, expensive parts (£150 for piston ring kit) ) but to ride on a sunny day, embarrassing boy racers and guys on Bandit 600's and 400cc sports bikes on the twisties is just too much to miss. The sound of the bike at full chat was great, and I miss the smell of 2-stroke on a cold morning. I just love the way it put out a big white plume of smoke when it was started on really cold mornings.

To ride the bike is actually really good. It's very stable, and I only ever had one scary moment on it when I was cornering and the front wheel went into a rut on the lane I was blasting down. The bike sat straight up and I had a bit of a tank-slapper, but she sorted herself out. The suspension is well set up, the seating position is good (similar to an R6 with the back jacked up a bit). I have had pillion riders, and they were "unhappy" with the passenger seat, which has no grab rails, just a strap which I broke moving the bike, and the seat itself tapers to a point and slopes backwards, so not really a two-up bike.

The cockpit area does have a few problems though. The brake fluid reservoir partially obscures the rev-counter, the button to start the built-in lap timer is right under the button for the horn (which is pretty pathetic for an Italian made vehicle), and even though it was a UK bike, the odometer and trip meter were in kilometers, and the speedo showed KPH in big numbers, with MPH in 20mph increments on the inside in tiny yellow digits, which is quite difficult to make out at speed if you don't know what's where. The little computer thingy was great, with a combination race and lap timer (great for roundabouts), temp and time display combo and time display. Very handy. Also, the speedo can be removed with a couple of screws for track days, and the rev-counter and computer are mounted on foam, just like a big racing bike.

To look at, well, what can I say. It's big, really big, Yamaha R6 big, so it looks like a "proper" bike. My bike was matte black, which looked great, but started to wear after a year or so on the tank where I leaned on it. Other than that, the bike holds up well. It fell off its stand once, and the only damage was a broken indicator, which was superglued back together, and the bracket which holds the foot peg was bent in. £15 to replace secondhand.

Forget what people tell you about the RS125. If it's looked after, it will serve you well. This is a bike that you buy with your heart, not your head. I let my care of the bike fall behind and I paid the price. If your 17 or 70, I guarantee that you'll love the RS.

The bike is bearable, it'll never drop below 55mpg, will give you 150 miles to a tank and will put a grin on your face a mile wide. The lean angles that can be achieved are phenomenal, and the bike can really be chucked around due to it's light weight. Testament to the greatness of the bike, my mate's dad rides a Honda CBR1100XX Blackbird (Y Plate, currently showing a total of 3000 miles) which he has had from new and adores. But he would always nick my keys when I went round as he said it was such a giggle to ride.

Bottom line, if you want one, buy one. But don't expect to to hold up in the reliability stacks like the Honda or Yamaha unless you take care of it. Service every 5000km, use the proper fluids (synthetic 2-stroke, Super Unleaded etc), keep it clean and just generally respect the bike.

I am now missing the bike so much, that I have decided to take my full bike test. RSV Mille here I come!

Would you buy another motorcycle from this manufacturer? Yes

Review Date: 10th July, 2006

16th Sep 2008, 11:01

I have the RS 125. Can I put the power valve system on my bike?

9th Oct 2008, 17:00

I have a 2007 RS125, mechanically the same as the older model, and it has been very reliable, using the expensive 2T oil (Castrol) and allowing 3 bars and then 2 miles before opening her up. (New dash has bars instead of numbers)

I wouldn't say I ride it 'carefully', as it's derestricted, without riding it hard the plug just fouls up, causing problems on starting and everything. Allowing it to run low on oil also can cause air blockages in the oil system, which can lead to oil starvation (as seen on a Pug scooter that was in the workshop recently, I work as a bike technician), so I keep mine above half full and tend to throw a capful into the tank (and shake it about) for good measure.

Just respect the typical 2 stroke ownership morals and it'll be a very reliable machine.

20th Apr 2009, 18:44

Which is quicker, an Aprilia RS125 or a Kawasaki er5?

23rd May 2009, 11:25

Hi, I'm just wondering what's wrong with my bike because it's seized twice with in 1000 km. Please help me.

1st Apr 2010, 10:45

Hi, I have an RS 125 2000 model. When the engine has been running for over half an hour or so, the engine temperature never goes over about 40 degrees C.

The temperature sensor works perfect. Can anyone tell me what's wrong with it, do you think it's the thermostat?

Could you please email me back on motocrossmainiac1991@yahoo.co.uk

And if it is the thermostat, where is it on the engine?

Thanks, Luke.

7th Sep 2010, 09:15

Seriously doubt you would embarrass a B600.

2001 Aprilia RS125


Awesome, Italian, screaming rocket


"Clutch basket"? fell off on day 2!!! Resulting in a total loss of drive.

Speedo drive broken at 8000km.

General Comments:

I took a lot of time deciding which bike to go for with my provisional license, and after choosing between a Cagiva Mito and the RS, I was pleased with my choice.

So it's a 125 we're talking about, not an R1, but for what it is, it's a very quick bike.

It handles like a dream and doesn't look embarrassing when you're riding with bigger bikes. In fact around twisty roads, it can get embarrassing for big bikes to see you come flying past!

On the whole, I have had very few problems other than the clutch, which the dealer refused to collect, leaving me to get it 60 miles back to them! (not happy)

The only bad point I can think of, is the lack of a fuel gauge. There is a reserve tap, so once the bike runs out, you can flick the tap and get to a garage. But when you run out of fuel passing a car on the wrong side of the road, it becomes dangerous! I know!!

I wouldn't buy second hand because they need looking after. Run it in properly and gently, only use fully synthetic oil, and don't so much as touch the throttle until it is warmed through! Obey the above rules and it will last you a long time.

If it's a sports bike you want, and you don't have a full license, then this is the bike for you.

I loved mine so much, I have ordered another (2006) to commute to my new job, and I pick it up a week from today! I really must do my test!!!

Would you buy another motorcycle from this manufacturer? Yes

Review Date: 22nd March, 2006

27th Jun 2006, 13:52

The previous comments on the Aprilia RS125 were outstanding... from gentle running in right down to the use of full synthetic oil, this person really is a RS125 rider, Rossi would be proud. Only a true RS rider would know about the speedo cable problems and the way on a twisty road it is possible to leave 400cc riders smelling that sweet aroma.

Standard RS125's can look even better with little cost, just by polishing the end can. Riders be warned that going too fast over humpback bridges can set you back when it comes to buying a new mono shock.

N.B. The New Irish provisional licence will not allow you to ride a RS125 (unless restricted). Bring back the old days.. :)..

2001 Aprilia RS125


Nothing went wrong while I owned it.

General Comments:

Bought this bike from new because I like its looks and wanted to try a sports 2 stroke.

After 3 months I hated it, and sold it on

with less than 1000 miles on the clock.

Simply could not live with the peaky 2 stroke performance, although for a 125cc, it goes pretty good.

Handling is about as good as it gets for a bike, and its beautifully built.

Needs pampering with the correct oil - MUST be

Putolene according to the dealer, and needs careful warming up or else the warranty is void..

Did not own long enough to have any problems, although I have heard stories of blown engines after 12,000 miles etc.

Would you buy another motorcycle from this manufacturer? No

Review Date: 22nd February, 2006