Our BSA Bantam Connections

We have hundreds of customers who own one of the BSA Bantam range of classic motorcycles. In fact the first vehicles to operate with one of our ignition systems were a BSA Bantam D14, a Sunbeam S8 and a Triumph Herald car. Because of our early links with the BSA Bantam we called the product Rooster Booster, which caused one of our customers to say that their Bantam had more 'Cluck' after installing the module.Today we provide several different ignition solutions for the various Bantam models and have created this page especially to provide information about the electrical and ignition system and how it can be improved on these machines.

Bantam Rectifiers and Regulators

Although your Bantam was originally fitted with a rectifier, it was NOT fitted with a voltage regulator. This is the reason that so many Bantams have problems with bulbs blowing and batteries overcharging. The original plate type rectifiers are by now way past their 'sell by' date and may not be running as efficiently as they should. You could replace the rectifier with a standard solid state square bridge rectifier which we sell for £4.50 but this is NOT our recommended course of action.

Instead, we recommend you replace the rectifier with a combined Regulator Rectifier. These are available in 6v and 12v variations and cost just £34.00 including postage. It will keep your battery in the best possible condition and ease the problem of blowing bulbs. In addition it allows you to run third party electronic equipment such as Electronic Ignition, LED Lighting and Sat Nav. Without a voltage regulator you may damage any modern electronic equipment you fit.
For D1-D7 Bantams with the coil integral within the generator, you do not neccesarily have to install a voltage regulator to use our Rooster Booster Junior Electronic Ignition system but we still advise you to do so for the aforementioned reasons.

Which Rooster Ignition System Do I Need?

If you own a D1-D7, then the cheapest option is to use our Rooster Booster Junior Module (RBJ). This module is small and compact and uses self timing technology to produce much improved ignition performance. The unit has a very easy two connection installation and costs just £25.00 including worldwide delivery. Some D7's were fitted with a standard external ignition coil (twin switch models) and these will require our Rooster Booster RB1. The RBJ does NOT need a battery installed to operate so is also ideal for trials use.


If you own a D10, D14 or a B175 (excluding the Bushman model) then the cheapest option is the Rooster Booster RB1. All Bantams left the factory specified as 6v with Positive Earthing. This means that the exact model you require is an RB1-6P. This ignition system requires that your Bantam has a battery fitted and that you also have a voltage regulator fitted. The RB1-6P costs just £45.00 and our RR6-150 combined regulator rectifier module costs £34.00 including delivery. If you have converted to either 12v or Negative Earthing then please let us know so we can supply suitable modules.
If you own a Bushman then unfortunately we do not have an ignition system for you at this time, unless you convert your current ET ignition system to a standard DC version (please contact us for details).

How do I upgrade to 12v?
On a Bantam the upgrade to 12v electrics is fairly simple although you first should ask yourself WHY?
If you just want brighter lights then we can supply very bright Halogen 6v bulbs that will fit your existing sockets with no further modifications.(also available in 12v)
If you still want to change to 12v on a D7(Dual Switch Model), D10, D14 or a B175 (excluding Bushman models) you will need to upgrade the following items:-

12v Regulator Rectifier Module - RR12-150 (£34.00)
12v Battery - Unfortunately we do not sell this item.
12v Ignition Coil - RC12-1A (£21.50)
Full set of 12v bulbs - Various Options and Prices
12v Horn - rhc1-1 (£10.00)

We do not recommend upgrading D1 - D7 (Single Switch Model) Bantams for 12v operation unless you are installing a Bones CDI Kit.
Please visit our Documents page for suitable electrical diagram detailing the required modifications.
What are the best Spark Plugs to use?

We have found Iridium Spark Plugs to improve starting, be more resistant to 'whiskering' and to be long lasting.
All our Iridium Spark Plugs cost £11.50 including delivery. NGK Iridium part numbers are:-
Pre 1954 D1 (Originally L10, L86C, B6HS) - BR6HIX
From 1954 D1, D3, D5, D7 (Originally L7, L82, B7HS) - BR7HIX
D10, D14, D175, B175 (Originally N4C, B7ES) - BR7EIX

Other BSA Bantam Services We Offer...

Please visit our S55 Magneto page for details of our in-house generator repair and modification services.
We can also offer complete electrical renovation for BSA Bantams and other British Classic Motorcycle so please email us for further details.
We often have used Bantam electrical and engine spares for sale so please let us know if you need anything.