Please follow the instructions carefully, and use all tools listed
below, if you are in any doubt with fitting the kit in any way please
ask!
NoteThe Varitronic has variable timing and also sparks much more efficiently then any current electronic
system on the market, because of this you will need to re jet your carburettor to suit.
Tools Needed
Timing Light (Strobe Gun)
TDC tool
Torque Wrench
Timing disc or dial
gauge
32mm Ring spanner
10, 17 and 19mm
Sockets
Fitting the Stator
When fitting the stator plate initially affix the base plate in the centre of its adjustment. Feed the wire out through the top wiring plates, and secure the stator in place, make sure the wires are secured properly with the wiring tag and they do not rub the flywheel. Using a new woodruff key, temporarily fit the
flywheel and then find TDC on your scooter; the most accurate way is to use the positive stop method.
Once you have TDC, opposite the arrow on the flywheel, make a small mark with a marker pen or similar.
With a dial gauge, timing disc, or other accurate method you then need to measure out your desired timing (refer to instructions below for final timing settings).
Wiring The System In
Wiring depends on the wiring loom you use, the choices are original, replacement or electronic loom.
1) Electronic loom :- following the diagram sticker, the green from the wiring loom connects to terminal one from the CDI. The brown from the wiring loom should be joined with the yellow/white from the stator, and connected to terminal 3 on the regulator. All other connections are as per the diagram included with the kit.
2) Original or replacement looms :- Non Battery machines. The original green wire going to the coil will have a ring terminal on it. Cut this and replace it with one of the spade terminals provided in the kit. This wire goes to terminal one on the CDI. The other end of the green that was in the junction box, needs to be either left on its own in the junction box touching nothing or connected to nothing else, or taped up. The brown, purple and pink wires from the main wiring loom need to be connected together. The best way to do this is to use an electronic junction box, or a bolt and fit ring terminals to each wire, then then "screw" them together. Make an extension wire from either the junction box, or the joined wires and run this to the regulator. The extension wire needs to be joined to the white/yellow from the stator and is then plugged into terminal 3 on the regulator. The rest of the wires from the stator should be connected as per the diagram. Fit 12v bulbs.
3) Original or replacement looms : Battery Machines. For original style battery machines where you want to retain the use of the battery for parking lights, horn and brake light should be as follows. The original green wire going to the coil will have a ring terminal on it. Cut this and replace it with one of the spade terminals provided in the kit. This wire goes to terminal one on the CDI. The other end of the green that was in the junction box, needs to be either left on its own in the junction box touching or connected to nothing else, or taped up. The brown and purple wires from the main wiring loom need to be connected together and are then joined by the yellow/white wire from the stator and are connected to terminal 3. The grey and red wire from the main wiring loom also need to be connected together, and they go to terminal B on the regulator. Do not forget you need to fit a 12V battery, bulbs and horn!
In all instances careful attention to the earths are needed, the Varitronic requires all earths to be correct and present!
On the Varitronic loom from the stator, the blue connects to the regulator, and then links to the coil as shown in the wiring diagram. The important part of this earth is that this must also go to the scooter frame, and then back to engine casing to complete the earth. We suggest fixing on the frame leg, and then a cowling securing bolt, both of which are where the original earth es would have been. Make sure the rear light is earthed properly to the frame, the headset earths are correct and secure.
Fitting the flywheel
Using a new woodruff key fit the flywheel onto the crankshaft, please note the flywheel requires a 32mm ring spanner as a holding
device to lock it while you tighten the flywheel on. Torque the flywheel to
50lbs anti clockwise using a torque wrench, this is important! Now you are
ready to check and set the timing, using your strobe gun (or timing light).
Setting the timing
There are two versions of the stator plate, earlier versions
1) These have a slot with A & R marked each side.
2) Later ones can be identified by having six increments marked on the stator and feature more choice for timing settings.
To set the timing proceed as follows
(1) Early :- These plates need to be set to maximum advance, achieved by rotating the stator plate fully anti clockwise. You can achieve further advance if desired by elongating the slots, but for the majority of applications this will not be needed.
(2) Late -: Initially the stator was set to the centre position. Start the scooter up (checking the flywheel nut is secure) and test where the timing is with your strobe gun. If you need to adjust the timing, take the flywheel off and rotate the stator plate. Rotating the plate anti clockwise will retard the timing, while the opposite clockwise will advance it. You should ideally refer to your tuner or kit supplier as to their recommendations on timing. Most Lambretta will be from 16 to 19 degrees at 7000 + rpm, please see the notes below on timing.
Notes on timing
Due to the nature of the Varitronic and the way it works, it can be tuned to your individual Lambrettas set up to achieve differing results. As with jetting a carburettor, adjusting your timing affects how and where your scooter makes power, handles heat build up, how efficiently it burns the fuel/oil/air mix e.t.c. Ideally you would set any timing system to the maximum advance you could possibly use without the scooter destructing by means of heat build up. With todays modern fuels, expansion exhausts, high compression cylinder heads, differing carburettors it is not possible to give an exact figure you scooters timing will need to be set to, the Varitronic is an additional tool to achieve more power while fine tuning your Lambretta. As with all static set ups, we can safely set the Varitronic to achieve an compromise end figure of between 15 to 19 degrees, and as long as you do this your scooter will be safe, reliable, and give more performance across a large percentage of the power band. How ever you can fine tune your Lambretta dependant on its specification possibly to give even more power, more reliability etc dependant on your needs, but this would normally involve some runs on a dyno.
