An SOF member rang me the other day to ask about the wasted spark system, as used on all my machinery, which prompted me to put pen to paper.

Some of our Beaming Friends also swear by this system, but there will always be the man who says it makes the machine non-original, but the beauty of this system is it can be converted back again at the side of the road with the swap of a few wires.

The bonuses are:-

• Works on 6v or 12v
• It is simple to fit
• It is cheap
• It dispenses with the rotor arm, the dizzi cap only acts as a dust cover
• The high-tension spark doesn't need to jump any gap
• Condensation and rain in the disc cap are not a problem
• The original coil can be left in place as a spare

Need I go on. It does not affect your statutory rights and your house is not at risk etc.

So how is it done?

The main component of course is a Japanese twin fire coil, this looks like a small block of yellow plastic with two HT leads coming out of one end and two thin wires going in at the side.

Now I am told by the knowledgeable that if machines are using electronic ignition then the coils are not suitable, I personally cannot see what difference it can make, but to play safe use a coil from an earlier machine that uses points.

Auto jumble price of such a piece should be £5-£10, in the J & S catalogue they are listed as £20 electronic or ports. The only other pieces are wire and HT leads, the latter is no longer available in Halfords, they look at you funny if you ask for copper wire HT leads, but they sell it at agricultural outlets.

The leads on modern coils are fixed in and may be long enough. I fixed mine under the top tube or the frame under the tank (yes, they are small) using two cable ties, the HT leads coming down to the plugs so no back tracking of rain in a storm, but I have put my own leads in coils using Araldite to secure them.

So having mounted your new coil, either under the tank or in the box, this is the hardest part over. The two leads run to the plugs, it doesn't matter which one of the thinner wires is the live feed this will come from the ignition switch, the other goes to the low tension terminal on the distributor, again, it doesn't seem to make a difference which way round but, as a rule of thumb, most Japanese machines use black as their earth cable so this "earth's" out when the points are closed.

Now, I can imagine quite a few of you reading this saying it can't be that simple, but it is and it improves tick over and starting, it also helps keep those plugs working when on the overrun. So there you have it, the old HT leads and rotor arm, can be kept in the tool box and, if the original coil is still in the box, you will have a built in back up system.

Catch you later

Colin