Workshop services

Workshop services




Rex's Rewinds - Stator Repairs - Sparks Restored - Electronics repaired - Design, manufacture & Restorations.

We offer bespoke repair & rewind service for all motorcycle generators whether British, European, Japanese or American manufactured. We specilise in the repairs that others are not able to carry out. As electronics and electro-mechanical designers and manufacturers we have in-depth knowledge of electronics, ignitions and generating systems.

Click on Image below for pricing guide


In the first instance where we find a failed part we will attempt to source a new replacement part. If new replacements are not available we may be able to offer a repair or, if costs permit, manufacture a new part. We specialise in electronics and wound parts but do not work on motorcycles, because we are not motorcycle mechanics you will need to talk to your own model specialist or owners club for fault finding - we can take it from there and provide a new parts or a specialist repair service.


Our electronics workshops have a wide range of test equipment, from armature growlers, charging system analysis and ignition unit assessment equipment as well as machining capabilities & CNC production mahines. We are a design and manufacturing company not a motorcycle repair shop and do not have the tools or equipment to work on complete motorcycles.

Sending parts to us

Please send your item to:

Rex's Speed Shop, Unit 1, Russet Farm, Redlands Lane, Robertsbridge, East Sussex, TN32 5NG, United Kingdom.

If sending parts for repair from outside the EU, we strongly recommend that you declare the value of the parts as their scrap value, after all they aren't working! 

Any Import Duties will be added to your bill


If you declare a high value, high charges will be payable and we have no control on this. Using a fully tracked service such as FED-EX will give the best assurance that your parts for repair will arrive safely, even where a low value of goods is declared. Note we will not accept parcels with excessive Duty charges, IE those over £75 without prior written consent from the owner. 


We accept most major credit and debit cards over the phone or we can send you a secure payment link via e-mail. The payment link works well for overseas customers but you may need to contact your bank and inform them that you wish to pay a UK company.

Alternately you can pay by bank transfer in £ Sterling or € Euros - please ask for our bank details and which currency you prefer. It would be helpful if you would like to be billed in Euros to let us know when you send your parts to us.

Trade sales - to obtain the best discount payment should be by bank transfer.

Unfortunately we no longer accept cheques

How Long Will it Take?

We aim to look at work sent to us and give an estimate of cost as quickly as possible, usually within three days of receiving the part(s). However, our workshops get EXTREMELY busy at peak times, while some jobs can be turned round quickly we are a small family business with a limited number of suitably skilled people who are able to carry out the worked required. This means that there is a waiting time for the work to be completed, the length of which depends entirely on how busy the workshops are.

Below is an estimated forecast of lead times based on past experience. Obviously we have no control over how much repair work is sent to us so lead times may change on a weekly basis. Please note that asking for 'up-dates' on the progress of work in progress will only increase the time techs are away from their workbenches and NOT getting through the actual work, therefore Techs do not come to the phone, if you require an 'up-date' it must be e-mailed to the technical team.


Estimated workshop lead times 2018 - subject to change without notice. 

What does testing cost?

Basic tests: Simple tests with a multimeter - Free of charge. Typically these take less than 3 minutes to perform. Opinions based on such basis tests are just that - an opinion - not definitive or binding, simply an indication of where the problem may be.

In-depth test: We are able to give more in depth analysis by the use of more specialist test equipment or carry out further inspection by striping the item down, however we will charge at our standard workshop rates, with a minimum one-hour charge for this. We will always notify you of the likely cost of such testing.

Generators & Regulator rectifiers

Assessment of generator and/or regulator rectifier performance in the test cell with the generator being driven at its design speed by an electric motor usually takes 1-4 hours depending on the part(s) under test. Any engineering costs to manufacture adaptors so the generator can be mounted in to the test cell (if we do not have these already) are an additional cost.

Testing of analogue CDi units

We have fixed fee of £20 +VAT for most testing of analogue CDi units. Our comprehensive workshop equipment that allows us to bench test older CDi units, both statically and dynamically. Many CDi units over 15 years old will have dried out capacitors inside them, causing low spark power or in some cases lost or inaccurate advance curves. Static testing will show if the unit produces a spark and only gives an indication of power left in the unit, this type of test will not check the timing curve. Only dynamic running will show advance curve faults. Static tests are charged at one fix fee. Dynamic testing on average takes 1-2 hours on average depending on the system. Any engineering costs to manufacture adaptors so the generator can be mounted securely on to the test cell (if we do not have these already) are an additional cost.

-Resin filled CDi units are not repairable-

Rewind Pricing Guide (click on the picture to open a PDF document)

Click on the image below to open our pricing guide, it links to a PDF document.

The price for a rewind refers only to reapir the windings within that component. Time spent removing windings from mounting plates, repairing threads and leads etc, then subsequently to reassemble the component is charged at our standard workshop rates, based on the time taken and in addition to the rewind cost.


We repair mechanical, electro-mechanical & electronic component parts, however we do not have facilities, tools or insurance to take in complete motorcycles for repair. 

  • Testing & diagnostic check of generators & ignition systems
  • Turning, milling, general fabrication and welding service
  • In-house re-insulation, CNC & manual winding capability
  • New parts and windings for generators manufactured
  • Alternators with slip rings and brushes repaired
  • Reclamation, restoration and refinishing
  • Lucas Rita "Revival" service
  • Electronics manufacture
  • Payment accepted in £ GBP or € Euros



1. Include your contact details as well as a phone number or e-mail address. It can cause considerable delay if we are not able to contact the owner to obtain authorisation to proceed with work.

2. Please include a brief description of the service you require.  Be sure to include more information than "as per telephone conversation here's my generator" as it is unlikely the person you spoke to book the part in to our system. Also we speak to many people each day often regarding similar items. If you have e-mailed us, a copy of the e-mail in with the part is helpful.

3. When sending from overseas, IE the USA or Australia, the value you declare on the parcel may cause import duty and VAT to be applied. Be realistic of the value of a failed, second hand unit as any duty we have to pay will be added to your bill in addition to any quoted price for the work.

4. When sending plain type CDi source windings for repair, if there are two mounted one above the other, we require BOTH, even if only one is to be rewound.

5. We do not recommend that TZ or MX type generators are stripped by owners. These systems can easily be assembled incorrectly leaving you with a system that looks right but simply will not run. Sorting this out is time consuming and expensive. 

Repair work is chargeable per hour and workshop prices are always quoted excluding VAT.

Trade Customers

We are happy to work with motorcycle repair shops. You will need to open a trade account and prove that you are a genuine business with business premises. All trader invoices must be settled by bank transfer to recieve the best trade rates.

We will look at any Japanese, Italian, German, American, Hinckley Triumph parts and Lucas RITA boxes but regret we do not work on British magnetos. 


Alternators with Rotating Field Windings

Many Classic Honda, Yamaha & Suzuki machines had alternators with brushes and field winding that spins on the end of the crankshaft, for example the XS650, 750 & 850 and Suzuki GT750 and well as many Honda models.

We are able to overhaul both the stator and rotating field winding. The rotating core is CNC wound with copper and a high strength fiber. The winding is then over-wrapped in a specially woven fabric. The assembly is treated with resin under a VPI process to ensure thorough resin impregnation. Both the fiber and fabric soak up resin to form an incredibly strong composite which ensures the windings have increased resistance to centrifugal force. 

Slip rings are checked and their surface can be restored even if pitted, worn or burnt. Finally we check the alignment to ensure the rotor runs true. We can supply brushes for many of these alternators.






TZ, MX and Race Ignition Systems

Racing ignitions require careful repair to get the best from them.  Our CNC machines give the exact number of turns, wire tension and even layer build up. We have a wealth of experience with racing ignition systems and over the years we have carefully catalogued each one to create an extremely comprehensive reference database.  As a result we can offer fixed price rewinds and fast turn rounds of these systems.

We can perform basic static checks to see if a unit operates or full dynamic testing of ignition units to check the advance/retard function is working correctly. For some systems we can alter timing curves. We can supply new ignition units or put modern electronics in to original cases to maintain original appearance. 

Ignition Unit Testing & Repair

We are able to test many older transistor and capacitor discharge boxes on the bench. Some repairs are possible where the electronics are not set in resin. If the electronics are fully encapsulated generally no repair is possible. We are able to manufacture an increasing range of new, replacement units to replace failed ones. Many Japanese ignitions from the 1970's & 80s multi-cylinder machines (XVs are a common example can be repaired). Please check with us before sending your unit for testing.

-Resin filled CDi units are not repairable-



Rex's Lucas Rita Service Centre

Coming Feb 18 - "Rita Revival" Service - All new, modern electronics to fit in to existing Lucas Rita boxes. Better protected against accidental connection and over volting by the vehicle's chargeing system, triple proctection on the coil drive transistor. Available for DIY fit or can be fitted by our "in house" Lucas Rita service center.

Full testing and health checks for Rita units. Accidental damage repaired, case polishing, lead replacement, connectors up graded to modern standards. All AB11 units can be repaired, we recommend that AB5 units are upgraded to AB11 (the Revival ciruit will do this if it can be fitted to the AB5 case). Full range of compatible HT coils, leads, caps and up rated HT coil diodes available. Available for; Moto Guzzi, Ducati, Moto Morini, Aermacchi, Hestketh and British motorcycle single, twin & triples (heavy duty version needed for triples). New diode packs available

Click on the picture for our guide on Lucas Rita testing and information


Bespoke Restorations

We restore many electronic parts to look like brand new original equipment with the benefit of modern reliability. This service is highly popular with restorers looking to achieve a perfect machine complete with its original electrics that work reliably. We offer:

  • Electronics design & manufacture
  • Plating & anodising to ISO standards
  • Blast cleaning and polishing
  • Welding
  • Turning and milling
  • Sourcing of rare NOS parts
  • In-depth knowledge of Japanese electrical systems

We work to standards associated with overhauling aircraft components to restore rare motorcycle parts to 'as new'. We have developed our own processes and equipment to strip and re-assemble parts without damaging them. We manufacture parts for vintage Japanese machines and do most of the restoration work in-house, including the production of modern, reliable electronics to replace failed originals.

When comparing prices, remember we do not cut corners. We don't use home brew plating kits as the finish is never as good and doesn't last like a professional finish. We control the design and manufacture of new parts at every stage and have a wealth of detailed knowledge regarding the inner workings of these systems.

Examples of our work:

Fully restored Kawasaki H2/A Solid State Magneto (CDI) assembly. 

First the cases are stripped of the old electronics which are then professionally zinc plated to ISO 2081. Modern electronic circuits are built and test run before they are sealed to the refurbished cases. The unit is fully assembled, tested on the bench and the work is completed with a new set of decals and lead idents:


Kawasaki H1/D Stator rewind:



Manufacture of new stators, self generating ignitions and generator parts

Newly manufactured Honda RS500 stator:



Fully repaired and rewound TZ250 4DP generator stator:


'Restored & reloaded' KH400 CDi unit. New electronics, case professionally replated to ISO2081, new leads & connectors backed by a one year warranty:


Rare DT2-MX points magneto fully restored by Rex's Speed Shop technicians. This model was normally fitted with electronic ignition but there was a points option for USA models. Its a very high quality competition magneto, with 2 charge coils to supply one set of points. We have in stock points and condensers for this magneto.