Peugeot Speedfight 2 Scooter de-restriction procedure.
As described, was done on a 2002 model. This post is in reaction to the frustrations of finding huge numbers of search hits that never lead to an actual explanation. With care, it can be done without any welding. DIY mechanics look away. This stuff is for the hard up newbies and the faint-hearted. Without apology, its an expansive explanation!! OK - here goes..
1. You need to have some basic tools (spanners, sockets etc.) and a flat comfortable place to work, and access to a large bench vice. We plan to squash the exhaust disruptor resonator flat - but in a tidy way. In place of the vice, a club hammer and a piece of girder. The total DIY downmarket pits can settle for an up-ended brick, and at least a hammer of some sort. You need to be a bit inventive/creative at times to solve problems like corroded-in bolts, and awkward access. It helps hugely to have a Haynes or similar manual (eg. £14 from Halfords in UK) The manual does not describe what to do about the exhaust modification other than say take it to your dealer, but it does describe the variator assembly and restrictor plate, and also what bits to take off to get at these things. A bit hard to decode which pictures belong to this model, and one has to use several different sections of the manual to put together what we want to do, but it comes with PICTURES :)
2. First understand it. The exhaust device that makes the engine choke up when it gets to certain revs is a small tube stub roughly 15cm. long and 2cm. wide, welded onto the exhaust at a place between where the exhaust attaches to the engine, and the first silencer expansion chamber. Its called a "resonator" and also a "disruptor". It's also fairly obvious why it is also known as "willy" or "dick". It is a "tuned" device in that its length is critical in returning pressure pulses that travel at the speed of sound in hot exhaust gas, timed to be in just the right phase to severely mess up (disrupt) the normal flow of gas through the exhaust. It sets up a standing wave in the tube. You can make it completely ineffective by crushing it - ie. squeezing it flat!
3. Lift the seat, and carefully pull up to unclip and remove the plastic tool tray thing above the fuel & oil filler caps. Take care not to damage the side parts that have a little cut-out each that meets the panels. It is quite stiff, pressed over a chassis tube, but it does lift out with a "snap", and has no other hidden fixings. Carefully prise out the rubber grommet seal around the oil filler entry, and remove cap temporarily to do it and DON'T let anything like dirt or bits fall in! Avoid stabbing holes in the rubber with screwdriver ends and the like. Unscrew 3 flange head bolts holding the helmet storage compartment/seat assembly to the bike. I used a M10 socket on a screwdriver type handle. You don't have to separate the seat from the storage box unless you want to. Temporarily remove the filler caps, (don't lose the fuel seal!) and lift it all out. You need to wiggle a little to clear the side panel plastics and the filler caps. Now put the caps back. Before you do anything more - we are supposed to disconnect the battery, and secure the leads safely. For many of us, the risks of messing with the battery connections, and the possibility of struggling to re-establish the terminal threading, or even dropping the fixing into the unfindable works is so high, we should leave it alone, and carefully stay switched off! Recognise you are dealing with a machine with maybe enough fuel in it to shove a large car a long way. NO SMOKING!!
4. Simply lift off the (now loose) flat metal heatshield and you see the exhaust attachment to the engine. The topside exhaust nut can be taken off easily, but the one under is more awkward. Note that the nuts use studding, which threads right through the flanges on the engine. While it is unlikely to unthread from the engine, it is possible seized up nuts can cause this. Take care, threads are weaker in engine metal. Many folk just leave the nut seized to the stud, and put it back like it is. Better to replace the stud and nuts if this happens. Use a squirt of penetrating oil to loosen them if they are stuck. Limit the forces you use. Try not to give yourself more problems by stripping the threads, or rounding the nuts with wrong sized spanners. I got the the awkward one using a 10mm socket from a nutdriver kit that had a screwdriver hex drive. I used one of the longer screwdriver bits as a short drive, just to hold the socket over the exhaust nut, and then turned the bit with a very small spanner (6mm or 1/4 inch depending where you are). It is important to slacken these nuts first. do not allow the whole weight of the exhaust to hang unsupported on the engine.
5. Now go for the other 3 bolts that fix the exhaust. Two are 6mm hex cap head bolts (Allen key style). These screw into aluminium, and are bound to be corroded in with white aluminium oxide. Worse, the torque to undo them is of the right order to strip the hex bolt into a un-turnable mess. Use penetrating oil (Plus-Gas, whatever) and wait. DON'T mess up on the hex driver size. Get it right. Apply force steadily and repeatedly, but carefully and actively watching and feeling so as not to damage the bolt. They can quickly turn a easy fix into a trial! Once out, consider replacing with stainless steel standard hex-head bolts. Put them back later with grease at least, or a copper-based ant-seize compound (like Copper-Ease), if you care enough.
The last bolt underneath is thicker (M8 needing a 13mm spanner), and has a nut. You need two spanners, or have one be a socket, because the bolt head will also rotate.
6. Take the exhaust assembly to a vice, and use it to squeeze the disruptor tube flat, starting at the sealed end, and working back toward the main exhaust pipe. STOP when you are about 20mm (about 3/4 inch) from the main exhaust pipe, to avoid tearing or cracking the welds open. If you can't get enough squeeze, you can (carefully) hammer it flat. This has even been done with a hammer and a brick, but we try to do better if we can! Any tiny remaining length is in practice completely ineffective in setting up back pressure disruption, and this method is easy, and avoids adventures with cutting and welding and sealing and corrosion problems. If you mess up here, all is not lost, but you need to cut off the mess and have the hole welded up with a patch.
7. Putting it all back is, as they say, nearly the reverse of removal. I refused to put back the corroded M8. I replaced bolt and nut with stainless. Put all the nuts and bolts on loosely, and then tighten up the flange nuts at the engine first, so things don't get stressed when you do up the others. Do NOT be brutal and over-tighten. Its only a little engine with little fixings. My small spanner, only 100mm (4 inches) one handed was more than enough for the engine exhaust flange nuts.
8. At this stage, I chose to put back the seat/storage compartment parts, not forgetting the little heatshield. You can leave it for later, after the rest of the work. If you do decide to drive it before removing the drive train variator restrictor plate, BE AWARE!!. You can be over-revving things very easily. The restrictor plate limits the amount the variator can make the belt ratio change. It would be like driving at max without being able to change out of first gear. Do it now if you can.
On the underside of the drive belt cover, there is a small bracket securing the brake cable, with a associated rubber fitting. It has a fixing screw near to one of the cover bolts. Take this one out first. It may easily strip threads, even on the way out. Be prepared to later replace it with a nut and bolt that goes right through the hole, if it cannot tighten. Remove the remaining cover bolts. One is somewhat behind a plastic panel. I used a socket with a short right-angle wrench, similar to Allen key, but with a square end to fit the socket. Pull away carefully. Note that there is a special locator (dowel) on the lower edge. The foot-start quadrant mechanism is all contained in the cover. You don't have to disturb any of it. Not also that the shaft end of the starter motor pinion locates into the bearing set into the cover you have just removed, and that it will take a little care to go back in when you put back the cover.
9. The forward pulley with the gear-toothed rim is it. The rear pulley has also the automatic clutch assembly, and you don't need to mess with it. The task here is to undo the centre nut while stopping the toothed ring from rotating. The Haynes manual shows a special tool of metal strap bolted between two casing bolt holes with a dummy tooth locking into the teeth of the ring gear. I used a big screwdriver shaft (any rod would do) held in the dowel hole, that as a fulcrum to support a flat tyre lever end stuck into the teeth. Its tempting, but not a good idea to try and jam at the teeth of the starter pinion, because the forces are high and the end is unsupported. It will easily break!. You could use the end of a large chisel, or even another big screwdriver. One way or another, you have to stop it turning while SOMEONE ELSE undoes the nut in the middle. Unless you have a special tool way of locking the pulley from turning, this is never something a single person has enough hands to manage. DON'T get careless about tool fit here. This is the territory of skinned knuckles and broken fingers, and rounded nut heads! Keep firm control!
10. Lift off the toothed ring, which is also one face of the "shallow cone pulley without a middle". You can easily remove the centre shaft, and the variator assembly, recognised by the three 7mm head bolts. Remove these with care, because the innards has 3 little guides that can easily fall out. The next plate to come out is the "restrictor plate", which will probably have the number 5.0 stamped into it. This is the bit you discard. Note that below it are 6 steel rollers covered in hard plastic material. There may also be streaked grease that has flung out and hardened. There may well be "flat spots" worn onto the rollers. I wished that I had had ready replacement rollers right then, but who can know they would have needed it before we took it all apart? Wipe off the grease with paraffin or solvent. Regrease with standard high melting point grease. DON'T cover it all in grease! You only need a very little on each roller, and a little smear up the ramps they ride in. Stay horizontal over a shallow pan or something. Make very sure the 3 small guides that go on the tips of the "ramp plate" go back located correctly. This is the point where you don't bother to put back the plate marked "5.0". Just go for the last one, which is also the pulley surface, and put back the 7mm head little bolts. ( I think they are M4 thread). Notice that the pully surface shows where the belt has been riding, and where it could go. It looks a bit like a CD-R that has had data burned on in only a small diameter near the middle!
11. Nearly there!. Put it back, belt included. Make sure there is NO grease on the surfaces that touch the belt. Wipe with methylated alcohol (UK purple meths), and don't handle it with greasy fingers! I tightened the nut to 40Nm (30 ft.lb) using a torque wrench. It needs to be tight, and you would have got the idea from when undoing it, but don't overdo it to threaten the nut. Borrow a torque wrench if need be, or guess well. Getting the cover back on, with the dowel, is tricky. The problem is to locate the end shaft of the starter pinion gear into its place in the casing bearing journal. I found it was possible to hold the casing nearly correct, while sighting from the rear, using a small torch (er.. flashlight) to "aim" for the shaft, peeping through the gap. Putting one bolt in loosely at the rearmost point, to at least locate it at the right height, and keeping the cover pulled "away from its final home, allows you to fiddle. You know when it goes on right, settling all the way in with gentle taps. Simply sticking in the bolts and going for tighten-up IS A BIG MISTAKE!!. Having a few put in just a few turns is the excellent way to aid line-up. You have to be totally convinced that the dowel has settled in right, and that the end of the starter (smaller gear) shaft has located properly. If its all going on stiff, its probably in a problem which will rapidly get expensive! That said, a few bumps with the hand, and a little wiggle, and when it locates - you know it. Only then, go for the bolts. Again, only tighten appropriate to the size of the bolts. The really flash will have a torque wrench, and the torque data from the manual.
12. The very last thing to go back is the brake cable guide clamp. Its possible the screw will just turn uselessly in stripped aluminium, as seems to happen so easily. Don't dispair. A small bolt long enough to go right through, and a nut will do instead. 55mph, with a 50cc that has performance approaching a standard 100cc is what happens. Thats it - enjoy!
GTrax, July 2007
