Moped Tuning Guide (continued)

In our last article Stage 6 Pro Replica Exhaust Triumphs Exhaust Shootout ! we ran up some performance scooter exhausts on an otherwise standard Yamaha Aerox moped.
Today we're going to run up the best selling of the 70cc big bore sports cylinder kits.

Moped Tuning - What is a "Sports" Kit?

70cc "Sports" cylinder kits tend to be fairly mildly tuned but still offer a large performance increase over standard 50cc without really losing much in the way of reliability. Sports kits are by far the biggest selling big bore kits for mopeds. "Sports" kit manufacturers usually claim their kits make up to around 10hp, but take it all with a pinch of salt.

It isn't really possible to get much over 10-11hp on a 70cc moped without starting to significantly increase the revs, and if you do this you need to move up from a "Sports" cylinder kit to a "Low race" kit, something like a Malossi MHR replica kit or Stage 6 Racing. These kits start to get much more expensive and parts start to wear much more quickly and the scooter becomes much less reliable for day to day use. Low race is about the limit you can use on the road as a functional bike unless you like working on your bike on a very regular basis !

For this article we've used just the main Italian manufactured kits (Polini Sport 70cc, Malossi Sport 70cc and Stage 6 Sport Pro 70cc) because the quality on all of them is unrivalled and spare parts, pistons etc. are readily available for them.

You'll notice that we've also included the Stage 6 Streetrace kit which is a budget 70cc cylinder with milder tuning than its Italian made Stage 6 Sport Pro big brother. It's proven to be a very reliable kit and at just £102 it's also a very popular kit, but is the performance any good at such a cheap price?
There are a lot of Chinese made budget 70cc kits which are sold under various brand names at around this price of very dubious performance and quality, so for those just looking for a budget 70cc kit we thought we'd give the option of a decent quality budget kit for comparison.

We've conducted the tests with the same Aerox moped we used in the previous article for consistency.
In general the results will translate directly to Piaggio mopeds also, the only really difference is that Piaggio engined mopeds normally make +1hp higher than the Aerox with otherwise identical cylinder kits or exhaust pipes fitted.
For the tests we've locked the variator drive so we can see what power the engine develops across the whole rev range.

Moped Tuning - Results

Our previous article concluded that the Stage6 Pro Replica Exhaust and the Leo Vince ZX exhaust were the best performing moped exhausts we tried when fitted to the otherwise standard 50cc Aerox.

(click to enlarge graph)

We also observed that because both pipes ran well at higher revs they would also be likely to run well with a more highly tuned 70cc cylinder kit fitted so for this reason we started out by testing all the 70cc sports kits with a Leo Vince ZX pipe fitted to see how it fared when faced with more highly tuned cylinder kits.

Here are the power curves with the Leo Vince ZX exhaust fitted in all tests.

(click to enlarge)

Moped Tuning - How to read the graphs

Mopeds use variators instead of conventional gears. The variator is designed to hold the moped engine revs dead steady by automatically changing the gearing whilst the speed of the scooter increases. If the variator is working well you can set it to hold the revs at exactly the peak power of the moped engine so as whenever you mash the throttle the engine goes straight to the revs at which it makes peak power and stays there. You can adjust the actual rpm that the variator holds the revs at by changing the weight of the rollers.

If we use the above graph we see the standard cylinder makes peak power of 7.4hp with the Leo Vince pipe at 9,300 rpms, so if we can set the variator rollers weight to hold the engine at 9,300rpm then we always have this 7.4hp available whatever speed the bike is going whenever we full throttle.
This would mean that we're only interested in the peak power each cylinder makes and the rest of the graph is irrelevant.

This is pretty accurate but there comes a point when the variator can no longer keep on changing the gearing. This point is reached at somewhere around 30mph for a standard 50cc moped (without gear up kit) and from this point on the speed of the moped can only increase if the engine revs also increase.
So in a drag race up to 30 mph the winner simply will be the one with the highest peak power so long as the variator is set up and working correctly, so Stage 6 Sport Pro would come first, then Malossi Sport, then Stage 6 Street and last in the Polini Sport.

Once we reach this 30mph mark the rules change... with the Malossi Sport, Polini Sport and standard cylinders you'll notice that the peak power drops off quickly after the curves reach their peak, so as soon as you reach the 30mph the revs increase and the power available also starts to drop off. Because you need much more power to accelerate swiftly at higher speeds what happens to the power curve after it has peaked is critical in moped tuning both for final top speed and acceleration between around 30 to 50mph.

So if we look at peak power again there isn't a huge difference... from the standard cylinder making 7.3hp to the Stage 6 Sport Pro making 8.8hp - the upgrade hardly seems worth bothering with at first glance, this is why peak power claims by manufacturers are a bit misleading. Let's look more closely at between 10,000 and 11,000rpm- let's say this represents a road speed between 44mph to 50mph. We can see now that in this speed range the standard cylinder drops from 5.5 to 3hp, the Malossi Sport and Polini Sport now look worth their money dropping from just 7 to 6hp. Despite having a peak power of less than 1hp more than the standard cylinder (up to 30mph) these kits now have 3hp higher at higher road speeds and will annihilate the standard cylinder bike at higher road speeds because of this.

However even with the Polini and Malossi kits the power still starts to drop off the moment the variator has fully moved out and cannot hold the revs constant anymore. The only way to get round this is if the power curve carries on horizontally after it makes peak power... and this is exactly what the Stage 6 kits do.

If you look at the Stage 6 Sport Pro kit it not only makes the highest peak power at the lowest revs (8.8hp at 8,800 rpm) but it is also still making 8.8hp at almost 11,000rpms, generating a full 33% more power than the more expensive Malossi and Polini kits at this speed. What's really surprising is that the Stage 6 street, one of the cheapest 70cc kits on the market is able to match it at this speed.

Conclusions

At lower speeds the Stage 6 Streetrace kit (£102), Polini Sport (£127) and Malossi Sport (£131) are almost identically matched but the Malossi Sport slightly has the edge. The Stage 6 Sport Pro (£124) is significantly quicker than all of them.


At higher speeds (approx 30mph up) both of the Stage 6 kits will considerably outperform the Malossi and Polini kits and they will also have significantly higher top speeds. The Stage 6 Sport Pro and the Stage 6 Streetrace will have about the same top speeds but the Sport Pro kit will get there quicker (is about 10% more powerful).

There is one potential problem with these results which you may be wondering about... In our previous article we found that both the Leo Vince ZX pipe and Stage 6 Pro rep were both extremely good pipes when fitted to a standard 50cc cylinder (hence we used the Leo Vince pipe for these tests). The ZX clearly works well with these 70cc moped sports kits but it's also quite likely that some of the pipes we tested which didn't perform as well on the standard 50cc cylinder as the ZX did were designed for use on a more highly tuned cylinder and consequently may work much better on these 70cc cylinders than they did on the standard 50cc.
For this reason we ran up all of the different exhausts from the previous article on all of these 70cc cylinders. Whichever exhaust we tried, the 70cc sports cylinders all finished in the same order, so whichever exhaust we used the Stage 6 Sport Pro came out top, followed by the Streetrace and so on.

Interestingly one of the pipes which was outperformed by the Leo Vince ZX in the 50cc write up was significantly better than the ZX pipe when fitted to every one of these 70cc Sports cylinder kits.
We'll do a proper write up next week comparing different exhausts when fitted to a 70cc Sports kit.

This article deals with Piaggio ignition fault finding where the scooter has no spark

Covers... All 50cc Piaggio and Gilera 2-stroke engines plus some geared 50cc (e.g. Derbi) which use the same ignition. It's assumed you have and know how to work a multimeter!

Testing for a spark

The best option is to use a spark tester which plugs into the spark plug lead (instead of the plug) and is clipped to an earth point on the moped engine. It will have an adjustable gap which the spark can jump across and the gap can be adjusted.

At its simplest you can check for a spark by removing the plug and resting its threaded part on a good earth point on the engine and either turn the engine over on the starter or kick it over with the ignition on. A better option is to connect the threaded part of the plug to earth with a jump lead to make sure there is a good connection and that the plug doesn't keep falling off.

*Unfortunately it is not enough just to see the spark plug sparking*. This is an important point- the distance the spark can jump directly reflects the voltage of the spark. If the spark is weak it's perfectly possible for the spark to be strong enough to jump the 1mm spark plug gap out of the bike and appear good, but not to actually spark at all when the plug is fitted.

Part of the reason for this is that a spark cannot travel so far in the compressed air atmosphere of the cylinder. This is especially true in more highly tuned higher compression moped engines. Also the spark simply may not be strong enough to ignite the mixture correctly.

For this reason it's necessary to check the spark voltage (how strong the spark is) and the easiest way to do this is by checking how far the spark can travel in open air. If you have a spark tester just keep increasing the gap until you reach the maximum distance the spark will consistently jump without missing, if it can jump minimum 7mm this represents over 15,000 volts and this will be fine for Piaggio/ Gilera engines but anything less is likely to cause running problems.

If you don't have a spark tester you'll have to improvise, you can screw two screws into a block of wood approx 7-10mm apart, connect one to the terminal up inside the spark plug cap with a wire and the other to engine earth.

Things to remember when testing...

• The spark plug may be faulty... always test with a plug you *know* is working or a new one
• It's not enough just to see the spark plug spark... the spark must be able to jump at least 7mm
• Try not to zap yourself

There is no spark, what next?

The Piaggio/ Gilera ignition is competely independent to the rest of the bike electrics. This means that it is unaffected by any faults in the charging system, battery condition, or any other electical faults and makes it pretty straight forward to fault find.

Click to enlarge picture


First to test the pickup (CDI red wire)
The pickup is located on the side of the flywheel and generates a small voltage everytime a nobble on the flywheel passes it. From the timing of this voltage 'pulse' the Piaggio CDI works out when to make the spark. Without this signal the CDI will never spark.
First we need to disconnect the CDI block connector as a faulty CDI can mess up the results.
Click to enlarge picture


Connect a multimeter set to read resistance (ohms) between the red wire and a good earth point (see pic)
Piaggio state this reading should be 80-90ohms, but it is nearly always 120-130ohms. You should get a reading between 85 to 140 ohms if all is well.

We've not yet seen a faulty one which has given readings within this range. The only other thing to check is the air gap between the pickup and the nobble on the flywheel. Rotate the flywheel by hand until the nobble passes the pickup and check the gap, it should be approx 0.8mm. Anything more than 1mm loosen the 2 mounting screws and move it closer. If there is no adjustment left you may have to bend it very carefully to get the airgap correct.

If you get this reading and the pickup gap is ok then the pickup is almost certainly ok and you can move on to the next section

If you don't get the correct reading either the pickup is faulty or there is a problem with the wiring between the pickup and the coil/cdi block connector. To check the wiring disconnect the flywheel/pickup/stator block connector and retest the red wire from there instead (see pic below for block connector location)

Click to enlarge picture


If you still get a bad reading from between the red wire here and earth then the pickup is faulty and the Piaggio Stator and Pickup assembly will need to be replaced.
If the reading is now good but was not good before there is a fault in the wiring, almost certainly in the flywheel block connector which tend to get damaged or corroded. This must be rectified before proceeding.

Testing the CDI earth (CDI white wire)
Disconnect the CDI connect block again and making sure the flywheel block connector is reconnected check the resistance between the white cdi wire and a good earth (or battery -(negative) terminal)

You should have a reading of 0 Ohms as the white wire should be connected directly to earth.
if so you can move on to the next section... otherwise read on

If not disconnect the flywheel block connector and check the white wire again from there. If you now get a good reading but didn't before then there is a problem with the white wire between the flywheel block connector and the cdi block connector, it will almost certainly be the flywheel block connector which can sometimes become corroded or damaged. This must be rectified before proceeding.

Testing the Piaggio stator output (CDI green wire)
If the pickup reading is fine at the CDI connector block and the white wire is earthed ok then we can move on to the green wire. The ignition key must be in the 'ON' postion for these tests. The green wire carries AC voltage (approx 80volts) from the stator to the CDI which is generated by the stator as a power supply for the CDI. This is completely independent to the other stator coils (not shown on our diagram) which generate power to charge the battery and operate the lights and are not involved in the ignition circuit.

QUICK TEST:- with both block connectors reconnected test the voltage between the green wire at the CDI and earth- if you get more than 50V AC when cranking the engine you can move on to the next section... otherwise read on

With the CDI block connector disconnected (but make sure the flywheel block connector is connected if you disconnected it previously) connect the multimeter between the green wire (at the CDI block connector) and a good earth point and set to ohms. You should get a reading between 600-1000 ohms. If you get an open circuit (infinite resistance) or short circuit (0 ohms) there is a definite problem (but carry on with the following test which will confirm it).

Next change the multimeter setting to volts AC and crank the engine over. If you get a reading of less than 50 volts AC (should be around 80V AC) there is a problem and you will need to repeat the test by disconnecting the flywheel block connector and retesting the green wire from there as we did before with the pickup.
If you can't get over 50V AC directly from the flywheel block connector you'll need to replace the Piaggio Stator and Pickup assembly.

If the reading is ok at the flywheel connector but not at the CDI connector there are 2 possibilities. The most likely is that there is a problem with the green wire between the flywheel connector and the CDI connector (almost certainly the flywheel block connector will be damaged or corroded)

If you look again at our diagram (click here) you'll see that the green wire also goes off to the ignition switch and the rev counter. To see if there is a problem here test the resistance between the green wire at the CDI block connector and earth with both the CDI block connector and the flywheel block connector disconnected. You should get 0 ohms with the ignition key in the 'OFF' position and infinite resistance (greater than 20M ohms) with the key in the 'ON' position. Anything inbetween these values demonstrates a problem with the key switch or tacho.

If all is well so far we have one more test. On Piaggio's it's still possible for the stator coil to be faulty even if it's giving us a healthy voltage when tested at the CDI block connector, so we need to do one more test to check that it isn't failing when placed under load.
Reconnector both block connectors and again test the voltage between the green wire at the CDI and earth. With the CDI plugged back in you should still have at least 50V AC when cranking the engine. If so all is well, if not and you have completed these tests correctly in order you'll need to replace the Piaggio Stator and Pickup assembly.

Done all that, still no spark- what next?
Ok, we've now confirmed that... you have more than 50V AC between the green wire at the CDI and earth when cranking the engine AND the white wire at the CDI has good continuity to earth AND there is between 80 and 140 ohms resistance at the cdi plug between the red wire and earth (with the cdi disconnected).
This means you have eliminated everything except the cdi itslef and you'll need to replace the Piaggio CDI/ Coil Assembly. The standard Piaggio/ Gilera CDI is restricted to approx 10,500-11,000rpm which is pretty high and won't bother most people even with a sports 70cc cylinder kit and exhaust fitted. But if you need higher revs or are thinking of tuning your bike any higher in the future it's probably better to get a CDI with unlimited RPM (no rev restriction) such as the Athena De-restricted Piaggio CDI

Piaggio Parts

Piaggio Parts, Stage 6 Parts

We've had these pipes in for over a year now since they came out.
They've been sitting in the showroom gettin dusty next to the even dustier moped handguards (which Ricky promised us would be a sure seller), so we thought it was about time we ran one up to see what it would do.
To be honest we've never really tried very hard to sell them.

"What's that ?"
"It's the new Leo Vince GP"
"Is it any good?"
"Er...Dunno"
"Have you got any ZX's?"
"Yeah I'll go and get one"

A brief explanation of powerpipes

2 stroke engines are all about the exhaust.

On a regular 4 stroke engine air/ fuel mixture is drawn through the carb into the combustion chamber (cylinder) due to the suction created as the piston goes down.
But if we could cram more mixture into the cylinder than it would normally draw in naturally it makes sense the engine would produce more power.
On a 4 stroke engine we can do this with a turbo charger. A turbine spinning at up to 2,000 times per second stuffs more mixture into the cylinder under pressure than it would otherwise draw in naturally which increases the amount of mixture in the chamber (and effectively increases the compression ratio)
On a 2 stroke engine a perfomance expansion pipe exhaust does something very similar only without any moving parts. When the mixture is ignited on a 2-stroke the piston is forced down... on it's way down, the exhaust port is first uncovered allowing the exhaust gases to escape into the exhaust pipe and then the inlet port is uncovered allow fresh mixture to be drawn into the combustion chamber, but these 2 events overlap. This means that some of this fresh mixture is sucked not just into the cylinder but right through it and leaks into the exhaust pipe.
A well designed expansion powerpipe allows us to make use of this 'waste' to our advantage.
As the fat part of the exhaust reconverges (the back cone) a pressure wave is reflected back through the pipe forcing this fresh mixture back into the cylinder.. This effectively pressurises the cylinder with fuel mixture in a similar way to our turbo. The disadvantage is that a pipe can only work best at a specific rpm because of the timing involved and it takes some considerable skill to fabricate an exhaust which doesn't work well only over a very small rev range.

The pipe...

The pipe itself is very nice looking and probably the only moped exhaust designed to look like a MotoGP aftermarket exhaust. It's E-marked and road legal provided you don't remove the restrictor :)
In usual Leo Vince form it comes with a set of lighter rollers and clutch springs. The body sections themselves are immaculately tig welded stainless steel.
In fact this is its major selling point, stainless steel is expensive but it doesn't rust or corrode anything like a regular powerpipe will. There are virtually no other stainless steel powerpipes in production. With a regular exhaust all you can do is cover it with something to prevent corrosion but whether it's covered with lacquer or chrome plating sooner or later the covering corrodes due to the conditions it operates under leaving a very tatty looking exhaust often within just a few months. The Leo Vince GP should far outlast them.

All sounds good so far, but the most immediately apparent problem with the Leo Vince GP is that in common with standard moped exhausts there simply isn't enough room in it to contain both a full wave expansion powerpipe and a silencer, so compromise must have been made in its design which has to show up in its performance somewhere.

For our testing we used the same Aerox (otherwise standard) as we did for our exhausts comparison article STAGE 6 Pro Replica... to give us some valid comparisons.

(click to expand)



Results...

Amazingly this pipe was able match the peak power of the best of the other pipes. Let me put that another way, on a standard Aerox this pipe makes as much peak power (7.4hp) as virtually any other pipe on the market !
This means that if setup properly this pipe will perform as well as anything on the market up unto the speed at which the variator can no longer hold the revs constant (approx 35mph).
However as previously discussed we knew this pipe would have to have a performance compromise and this is where it is. As soon as the bike reaches this road speed the only way the bike can go any faster is by the engine revs increasing. If we look at the graph again we see that the power drops off very quickly after 9000rpm. In fact from 9,000 to 10,000rpms it has dropped 4hp from over 7hp to just over 3hp which is going to seriously limit the top speed compared for example to it's Leo Vince ZX big brother and because of this it will even be significantly outperformed by the Leo Vince TT which at £74.95 isn't far off half of its price.

Conclusion... who would buy this exhaust?

The best performing exhausts for an otherwise standard Aerox like a Leo Vince ZX or Stage6 Pro Replica will make maybe 50mph. The Leo Vince GP exhaust will perform identically to these exhausts up to approx 35mph at which point it will start to be significantly outperformed and will not be able to match the same top speed (although the top speed will still be better than standard). Also if you are later looking to upgrade to perhaps 70cc or make further tuning mods this may not be the best exhaust to pick because of its reluctance to rev. These are its only real downfalls.
It should however considerably outlast other exhausts because of its stainless steel construction (especially lacquered pipes) and it should be noted that it would probably work quite well with a gearup kit as that way the revs can be kept lower for longer and the high peak power at lower revs can be utilised to get back the missing top speed. Gear kits don't always work well with standard cylinder bikes but this should work well provided the rider isn't too heavy !

So where were we...
oh yes,
"Have you got any ZX's?"
"Yeah I'll go and get one"

Oy Mate, what's the best exhaust?

We get asked this everyday, so this afternoon we ran up some different scooter exhausts to compare.
The bike used was a completely standard 50cc Yamaha Aerox. It's important to note that these results are only relevant to standard 50cc. If the bike was further modified e.g. different cylinder kit etc. pipes that appear poor in this test could come into their own and vice versa.
We'll repeat the test at some point with different cylinder kits fitted.
Feel free to skip down to the results if you're not interested in the technicals !

The Technicals...

The pipes chosen for the test are popular budget pipes, more expensive exhaust pipes are designed to work with more highly tuned bikes and tend to work poorly with standard 50cc kits. For example the PM Tuning 360 and Yasuni R exhaust pipes don't perform brilliantly in this test because they're designed to work with much higher revving cylinder kits.

The first graph contains all the pipes tested for direct comparison. For the tests we've removed the variator and used fixed gearing to get a proper power curve for each exhaust so you can see exactly what power the pipe makes at different rpms.
The pipe which made the most peak power was the Leo Vince ZX and (suprisingly) the Leo Vince TT with the Stage 6 Pro Rep very close behind.

(click on picture to expand)


Of course things are never this simple and the pipe that develops the highest peak power isn't necessarily the pipe which makes the fastest bike.
Take the Leo Vince TT for example. You can see from the graph that it makes a very respectable 7.5hp at 8,800rpm. This means that if you play with the roller weights until the bike runs at 8,800rpm (a good variator will hold it there steadily) you'll have 7.5hp available whenever you mash the throttle and at whatever speed you're going. None of the other pipes can better this...
However once you reach a certain speed (approx 30mph on a standard bike) the variator has moved all the way out and will no longer be able to hold the revs at 8,800. This means that the only way the bike can now go faster is for the revs to increase.
You'll notice on the budget pipes (e.g. the TT and the Endy pipe that the power they produce drops off very quickly at higher revs.

If we look for example at 9500rpms we can see that the power for the TT and Endy pipe has dropped off to around 6hp already whilst the Leo Vince ZX and Stage 6 Pro Rep are producing over 7hp at this rpm. Because this rpm would represent a road speed of approx 35-38mph this extra 1hp can make the bike substantially quicker. 1hp might not make a huge difference when accelerating from 10mph to 15mph but accelerating from 35 to 40mph this difference is definitely noticeable and because of this the higher revving pipes are significantly quicker in the real world when fitted to an otherwise standard engine. These also tend to be the pipes that work well if you later upgrade to a 70cc kit which is normally designed to run at slightly higher revs than standard.

It's worth noting though that the lower revving pipes can be easier to setup. Take the Yasuni Z for example, it makes more than 5hp all the way from 7000rpm to almost 10,200rpm, a range of over 3000rpm. The Leo Vince makes over 5hp only over a range of 2000rpm. This means that the Yasuni Z, although being a lower performing pipe will be very tolerant and easy to set it up.
Even if you get the rollers wrong and the variator is worn (can't hold the revs constant) it will still perform well as it's powerband is so wide

(click on picture to expand)

RESULTS

and so the conclusion...

• 
  

  Standard look Aerox exhaust

  
  To be fair, for the money this is a cracking exhaust. At £54.95 this performs far better than we thought it would and better than all other aftermarket 'standard look' exhausts we've tried. The power output is a substantial improvement over standard Yamaha making peak power of 6.4hp at just 7,700rpm meaning high engine reliability. Predictably though it does tail off at higher revs and therefore can't compete with the other pipes on top speed.

• PM Tuning 360 pipe

  
  Probably not a good choice for a 50cc standard moped especially give the price of £136 for the laquered or £159 for the chromed version unless you're planning on tuning further at a later date. It has a surprisingly broad powerband though, this pipe will be much more interesting when we test it later on some 70cc kits.
• 
  

  Leo Vince TT

  
  At just £75 this is an impressive exhaust. It's power curve is almost identical to that of it's ZX big brother except it occurs approx 800rpm lower meaning that it looses out to the ZX in top speed but should match it and any of the other pipes neck and neck up to around 30mph. This is definitely a best buy at the price. The Endy pipe isn't far behind and is cheaper at £70 but the TT comes complete with light roller set and clutch springs which the Endy doesn't. Both Endy and TT pipes are probably best avoided if you intend to upgrade the bike to 70cc as they perform best with standard 50cc
• 
  

  Leo Vince ZX

  
  This is a classic exhaust but it really does deserve it's popularity. Together with the Stage6 Pro Rep pipe these two pipes stand out as producing the most useable power both peak power and the power developed at higher revs meaning both the best acceleration and best top speed. Currently £99 for the laquered version and £119 for the chromed version this is more expensive than the Stage 6 pipe. There is now a ZX-R version of the Leo Vince out, but first impressions are that this is no better than the original ZX. Whereas the ZX was mostly hand welded, much more of the ZX-r process now seems to be machine automated and first impressions are that it's a cost cutting exercise rather an a genuine new pipe. We'll run one up shortly though for comparison before committing to this !
• 
  

  Yasuni Z

  
  This was a bit disappointing to be honest. It was outperformed by even the far cheaper £70 Endy pipe. We know this pipe doesn't work well on anything bigger than 50cc so this was it's best shot. Yes it has a very broad powerband but this simply isn't that useful. It will be more tolerant of a poorly setup bike, but a 50cc moped really isn't that hard to get right. The Yasuni R was more interesting and curiously was able to develop more hp than any other bikes at 11,000rpm but even so for such an expensive pipe it is easily outperformed by the ZX and Stage6 pipes. In fairness we know this pipe works extremely well on higher power cylinders right up to MHR rep/ Corsa/ Stage 6 70cc Race which are too highly tuned for pipes like the Leo Vince ZX to work well on. Because of this it's still one to definitely consider if you're going to be doing some significant tuning !
• 
  

  Stage Exhaust Pro Replica

  
  This Stage6 exhaust really has to be the outright winner. It's very similar to the Leo Vince ZX pipe but the Stage 6 pipe has a wider powerband at an expensive of just 0.2hp loss of peak power over the ZX. However the broader powerband importantly comes into play at higher rpm and develops more horsepower than the ZX pipe as soon as the variator has finished changing out making it marginally slower than the ZX up to approx 28mph but from then on it develops up to 1hp more than the ZX from there onwards. This alone would make it the winner in our eyes but it is also significantly cheaper than the ZX. £99 gets you just the lacquered version of the ZX pipe whereas £99 would also buy you the chromed version of the Stage 6 exhaust. The chrome version of the ZX pipe is an extra £20 and is in the process of being discontinued presumably to save costs (currently Leo Vince have their exhausts sent out to be chromed by a 3rd party). It's worth noting though that the ZX pipe comes complete with rollers whereas the Stage6 exhaust doesn't (budget extra £6!)
  For such a high performing exhaust at such a good price you really can't go wrong

Here are a few photos from this years trip to the Intermoto in Germany.


Click here for Intermot pics

Stage6 Parts

We are now stocking high levels of Stage6 moped tuning parts. Stage6 are a German brand and manufacturer quality scooter performance parts. They specialise in Aerox, Speedfight and Zip/NRG.

Stage 6 Exhausts

Stage6 Pro Replica Exhaust - Aerox/Minarelli
A high-performance Stage6 exhaust system for 50cc and 70cc with CE-mark for an unbeatable price.


Brake Disc Stage6 WAVE Oversize 240mm - Aerox
Wavy 240mm oversize brake disc from the Stage6 Styling Parts.