OK, this is NOT a definative Scooter tuning guide, nor does it delve into the best combination of Jets, Rollers or Tyre compounds. There are too many combinations to contemplate, so I’ll stick with a nice simple overview of what you really need to know.

First, the nasty stuff.

Legalities

You must be aware that at 16 you are only legally licenced and insured to ride a 30mph Moped, assuming you have a CBT.  That means no go-faster modifications, or you are risking a total loss of licence and when you get it back, prohibitive insurance costs. THE COURTS ARE FULL OF PEOPLE WHO THOUGHT THEY WOULD GET AWAY WITH IT!

At age 17 or more, you can ride a 125cc UP TO 14BHP unless you have passed a full motorcycle test. Unrestricted or Tuned Mopeds are fine too, although the 14bhp limit applies (No problem normally) and the machine should have been re-registered. CBT Riders are not allowed to ride tuned (Over 14bhp) machines, or those with Big Bore kits.

The penalties can be harsh! A driving ban for 12 months, Huge fines, and worst of all A CRIMINAL RECORD for riding uninsured. This may prevent you doing important things in later life….

The Usual Problems

The first thing to consider when tuning your machine is DO YOU REALLY KNOW WHAT YOU ARE DOING?
If the answer is Yes, then you will already know what a Piston ring is made from, including the difference between a Dykes ring and a Taper ring won’t you!
You will also know what exactly a Primary jet does, and what effect adjusting a C.O screw will have. You will know what C.O stands for even…

Being realistic, you won’t know these things unless you have extensive experience in a Scooter workshop, or have other experience of tuning two stroke engines.

If this is the case, it would be far better if you left the machine well alone, and enlisted the services of a specialist. This doesn’t include your mate who knows how to fit a Spark Plug…

The results of home-tuning are usually sloppy, with poor performance per-pound spent, and a sickly machine which doesn’t run as sweetly as it could.
Worse still, the life of the engine can be reduced by 99% as these engines can fail without warning within twenty miles in extreme cases.

In all cases of owning a tuned bike, expect heavier fuel consumption, a lower lifespan of serviceable components such as Spark plugs, Rollers, Belts, Tyres and Brakes.
Other components may fail suddenly, and destroy the entire engine!

IF YOU CAN’T AFFORD THE RISK OF SUDDEN AND TOTAL ENGINE FAILURE
DO NOT ATTEMPT TO TUNE YOUR MACHINE!

THE RIGHT WAY

Before going shopping, you need to check a few important things;

1/ Is your machine suitable for tuning, or is it a model which responds poorly?

Most Liquid Cooled Scooters are best tuning fodder, while Italian Air cooled machines are OK.  Japanese and Taiwanese air cooled bikes normally don’t go particularly well however.

2/ Is your machine in top condition?

Has it been professionally serviced and maintained? Is it low mileage and run on fully Synthetic oil?
IF NOT, THERE IS A HIGH RISK OF SUDDEN FAILURE or at best, it just won’t go fast because the tuning parts will never compensate for poor running.

3/ Can you really afford this?

Get a full price quote from the best local place. That is the realistic price…

You can shop around too, but never compromise on QUALITY or all your cash and efforts may be wasted, and leave you pushing your bike home.

4/ It’s going to get nicked!

Oh yes….If you were a young Pikey, you would love a go on somebodies tuned bike, so you could either stick a knife in his face at some traffic lights, or just help yourself one night as it was parked, you would do so. BE AWARE YOU ARE A TARGET!

Tuning Proceedure

I’m going to assume you have a derestricted 50cc two stroke Automatic…

NOTE; THIS IS THE CORRECT ORDER YOU SHOULD TUNE YOUR MACHINE. I HAVE MADE IT SIMPLE FOR THE IDIOTS AMONG YOU, BY NUMBERING THEM 1, 2, 3 ETC…

1/ BIG BORE KIT.

These are normally made by Malossi, but other eputable companies are Hebo and Polini. Avoid the Taiwanese big bore kits, as many offer no extra performance because they are cheap and badly ported. The Big bore kit raises your engine capacity to 70cc, and this offeres fuss free grunt unlike any other item. You normally need a mild rejet, but otherwise the bike will be faster in EVERY way.
This mod. is also INVISIBLE so attreacts no unwanted attention.

2/ GEAR UP KIT.

Now you have all this extra power (40% more at least!) you will find the bike gets to it’s top speed on the flat easily. No more ducking down behind the bars looking like a tosser eh?
The Gear up kit will give you a ‘5th Gear’ and raise the top speed by around 10mph, while improving fuel economy and cutting revs, giving the engine an easier time. THAT’S A RESULT OR WHAT!

3/ BIG CARB KIT.

Back to Malossi who make a bolt on kit…
Your big capacity Scooter now has the gearing and CC to warrant a bigger carb. This will not do fuel economy any favours, but will offer a fair bit more kick and some great induction noises, even with the standard airbox. It’s all but invisible, but boosts power by a noticable degree.

4/ EXHAUST.

Finally, the bit of kit you wanted in the first place, but was a waste of time and money until now!
With all those extra CC, and that big carb throwing in fuel like a 747, you need to get rid of the burnt gasses fast, and a big bore exhaust, such as the inexpensive Kundo 70 is just fine.
The downside is they don’t last for years unless treated very well, and they do make it a bit obvious the machine has been molested, but nevertheless the engine will open up a bit more, and run well as a result.

5/ TRANSMISSION.

You now have over twice the power you started off with, as an example, a 50LC Piaggio will have gone from 4bhp to around 10bhp if properly tuned, and your transmission is starting to show it’s weaknesses in the form of messy pullaway and sluggish gear ratio selection.
Only with your new found power will you need this, but invest in a Malossi (Or similar) Sports variator. This will enable you to tweak the roller weights to smooth out any flat spots in acceleration, and after this has been successfully tuned, consider a sports Cluth too, although this will have minimal effects other than a snappier pullaway.
Best of all, get a Malossi OVER RANGE set, which cosists of the front and rear pulleys and a belt which replaces the entire standard set up, and offers an increase in performance from pullaway to top speed. NO OTHER SYSTEM DOES THIS!

6. OTHER STUFF

In real terms, there is very little that is going to make any difference, and by this time you will have spent over £500 in parts alone, and it’ll be time for a 125.

However, ensure your suspension is in good order and tyres are kept inflated with plenty of tread. It’s funny how people spend hundreds on tuning parts, and ride around on cheap worn out tyres isn’t it.

Don’t try to ‘Race tune’ a bike for road use, as race bikes are just not practical or reliable enough. 20bhp is rather pointless if it goes BANG every week or two don’t you think?

The Crap

If you want to be laughed at, do consider the immediate purchase of ‘ANTI-PERFORMANCE PRODUCTS’

APP’s Are things like Neon tubes, Boost Bottles, Tyreflies, Red bull tins wrapped around the fork legs, Childish Turbo stickers (Only 10 year olds believe it) and (unless set up properly) Ram air / Open filters.

All these items are a waste of money and many of them actually DECREASE performance, which is something only a grade A **** would consider doing….

DO NOT CHANGE the order in which you tune your bike, as the results will vary from poor to non existant, meaning you will be wasting money.
AND IF YOU HAD THAT MUCH IN THE FIRST PLACE YOU WOULDN’T HAVE A MOPED WOULD YOU?

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This article was written by John Thompson of Piaggio Center
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