Kickstart Engineering

Kickstart Engineering, British specialist in restrictor kits for the A2 licence

Kickstart Engineering presents itself as the UK's only recognised motorcycle restriction specialist and operates under the domain a2restrictors.com. The company has supplied restrictor kits to both individuals and trade customers since 2010. Its kits are designed, manufactured and distributed in the UK itself and, according to its presentation, are independently tested.

The company describes itself as a preferred supplier to some of the largest motorcycle dealers, franchises, garages and training schools in the UK and Ireland. It keeps stock for immediate dispatch six days a week and offers a discount code to motorcycle dealers who request it.

Restrictor kit catalogue by brand

The catalogue is organised by motorcycle manufacturer. The 35kW (47hp) kits are available for models from the following brands:

• Aprilia
• BMW
• Ducati
• Harley Davidson
• Honda
• Husqvarna
• Hyosung
• Kawasaki
• KTM
• Suzuki
• Triumph
• Yamaha

Types of restrictor and certificate of fitment

Restrictor kits allow A2 licence holders to ride a more powerful motorcycle by reducing its power output to comply with the regulations for this licence. The company sells various types of restrictor: metal plates in the inlet or exhaust, throttle stops fitted in the twist grip or on the throttle linkage, and electronic restrictors.

All Kickstart Engineering restrictors are supplied with a fitting guide, with colour photographs where applicable, and a three-part carbon copy certificate of fitment for the installer to complete.

The A2 regulations and the 50% rule

On 13 January 2013 the A2 licence regulations changed from 25kW (33hp) to 35kW (just under 47hp), with a maximum power-to-weight ratio of 0.2 kW/kg. The company points out that this measurement is taken at the crank, not at the rear wheel.

Kickstart Engineering also explains a lesser-known inclusion in these changes: the limitation on which motorcycles may and may not be restricted, known as the 50% rule. This rule means that a bike cannot be restricted for A2 by more than 50%, so any bike with a manufacturer-stated power output of more than 70kW is excluded by law, and age-related power loss cannot be taken into account.

Under normal circumstances, if the bike weighs 175 kg or more dry, it can be restricted to the maximum of 35kW. On lighter bikes, provided the 50% rule is not exceeded, the bike can be restricted below 35kW to bring it legally within the maximum of 0.2 kW/kg. The company cites the example of the Yamaha MT-07: with a dry weight of 167 kg depending on the year, restricted from 55kW to 33.4kW it reaches 0.2 kW/kg.

DIY fitting and use in training and tests

According to the company's information, DIY fitting and certification are 100% legal, although the installer must be a technically competent person. Kickstart Engineering nevertheless recommends that the fitting is carried out by a motorcycle garage. That DIY fitting and certification are not accepted by an examiner for the A2 test.

For a test bike, the restrictor must be fitted and the certificate of restriction completed by a recognised motorcycle mechanic. The company also warns that not all insurers accept DIY fitting and certification.

Regarding use in lessons or a test, the company states that there is no problem as long as the restrictor has been fitted and signed off by a recognised motorcycle mechanic. It quotes verbatim the GOV.UK requirement: anyone who has restricted a motorcycle to subcategory A2 must bring proof; otherwise the test will be cancelled. That proof must be on headed paper, come from a main dealer, official importer or recognised specialist, and show the motorcycle's registration number. A dyno test certificate is not accepted as proof of the restriction.

Reviews from trade customers

The site includes testimonials from dealers and garages. Saltire Motorcycles highlights the service and that, when there was a delay with a kit, another was shipped out quickly. Alford Brothers Motorcycles mentions excellent service as usual. Skellerns Motorcycles notes that the part arrived as described and quickly. Billys Motorcycles values the service and recommends it. Other individual customers say that the product comes with paperwork to show that the bike is restricted, that fitting is very easy with clear instructions, that delivery was very fast and that customer satisfaction is a priority.