Workshop services

Workshop services





Rex's Rewinds - Stator Repairs - Starter Motor Repairs -

Alternator Parts & Repairs - Ignition Troubleshooting - Electronics repaired - Machining & Restorations.

Turn round times currently 3-7days on standard repairs.

We offer a fully comprehensive electrical component repair & rewind service for all motorcycles, American, British, European and Japanese. We are able to fully test and assess electronic parts. In the first instance where we find a failed part we will attempt to source a new, quality replacement part. If none are available we may be able to offer a repair service or manufacture a new replacement.  Our workshops only offer bespoke repairs, to OEM or higher standards. We have invested and are continuing to invest in machines and tooling so we can offer more rewinds done on CNC machines to give greater accuracy and a high level of reliability. Our electronics workshops have a wide range of test equipment, from armature growlers, charging system analysis to diagnostic equipment for classic machines. It must be noted that we are not a motorcycle repair shop and cannot take in complete motorcycles for work also at present we do not have equipment for machines fitted with ECUs.

What does testing cost?

We do not charge to use basic meters to check generators & components and give an opinion based on static tests. Static tests typically take less than 5 minutes to perform. Opinions given based on static tests are not definitive or binding and are intended as a ‘indication’ of what the problem and are by no means a definite diagnosis.

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.

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 securely in to the test cell (if we do not have these already) are an additional cost.

Testing of analogue CDi units

We have 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 only and give an indication of power left in the unit, but not if the timing curve is correct. Only dynamic running will show advance curve faults. Static tests are charged at one fix feed, usually the same as one hour's labour. 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-

It should be noted that if a bike runs on old CDi units (even NOS) but not a newly manufactured one, you must have the generator tested for weak windings or those in the early stage of failure. New CDi units have fresh capacitors which charge to 100% and will reveal windings that are just starting to fail. Capacitors loose their ability to store a charge with time, many old CDi units only charge to as little as 50%. Often this is mistaken as a fualty CDI, yet the true cause of the problem is inside the generator. 

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 precision manual and CNC winding service
  • Self contained alternators repaired (parts supplied)
  • Alternators with slip rings and brushes repaired
  • Reclamation, restoration and refinishing
  • Starter motors serviced & repaired
  • Undercutting of commutators
  • Lucas Rita units repaired
  • Electronics manufacture
  • Payment accepted in £ GBP or € Euros

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! This will avoid excessive import charges. Alternately, e-mail us to confirm that you will pay any import charges immediately. 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 quote an average turn round time of 3-10 days for repair work during low season and 2-4 weeks or longer in Summer. Restoration work will be longer, particularly if we have to make tooling to perform the work. We always try to return your component to you as quickly as possible. Our workmanship is second to none, we believe in doing the job correctly to ensure maximum reliability.

To reduce waiting times we offer a range of exchange generators:

New & Exchange Generators Available - Quick Turn Round

Workshop Hourly Rates
As of September 2017, our hourly rates are £45 per hour, plus VAT.

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 must be paid for by bank transfer, cards will incur a 3% surcharge


Unfortunately we no longer accept cheques.


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 will book the item on 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.

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.

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, our techs are often able to give in depth information to aid your mechanics with older or obscure  systems

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. 



Starter Motor Repair

We can repair many Japanese and European starter motors fitted to motorcycles and ATVs. We will strip and advise on what repairs are possible, if the unit has suffered a servere failure or been damaged by in-expert disassembly it maybe un-economical to repair it. We are able to supply brushes for many models.

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.





Self Contained Alternators

We supply new parts and repair self contained alternators that are fitted to many modern machines. We offer a "smart" replacement regulator that can be fitted in place of very expensive Japanese manufactured regulators. Our "Smart" regulator protects the alternator better than the original Denso regulator as it monitors the phase windings as well as the power the motorcycle's system is demanding and meets these demands without undue stress on the alternator windings.   

Parts books that cross reference which bikes they are fitted to are not easily available for these high power, forced air-cooled alternators. Therefore we need to see your alternator to determine what parts are used in it. We can obtain regulators, rectifiers, bushes and bearings for many of these units as well as our  'smart' regulator conversion.


Regulators repaired

The type of regulator pictured is expensive to buy new, it can however be converted to use a modern "smart" alternator regulator that monitors both the bike's system, the alternator and has protective features. Fitting must be done by our workshops as the new regulator requires connections to the phase windings and intial set up which needs specialist equipment. Typically the 'smart' regulator conversion costs half the price of a direct replacement. Externally there are no changes to the alternator's connections.

Many other direct replacement regulators are available 'off the shelf', these are supplied at very competive prices and are available for the customer to fit themselves, or our workshops can do this work for you.


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-



Lucas Rita Service Centre

Our in house Lucas Rita service center offers repairs from one hour's labour +VAT. With no 'middle man' we offer good quality at sensible prices, also the chance of your unit being lost is reduced as we do not forward these to other comapnies for repair. Our services include; main transistor upgrades, dead units revived, accidental damage repaired, case polishing, lead and connector replacement. All AB11 units can be repaired. and some AB5 units are best replaced. Full range of compatible HT coils, leads, caps and up rated HT coil diodes available. All car systems, Moto Guzzi, Ducati, Moto Morini, Aermacchi, Hestketh and British motorcycle systems catered for.

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.

Wiring Looms

We are able to manufacture one-off wiring looms. We do charge a design and set up fee of 4 hours labour +VAT to research and produce a wiring digram. We will supply this to you for you to build or we can go to the next stage and manufacture the loom itself. This then starts from 10 hours labour+VAT for a very basic stripped down loom. The remanufacture of an exact copy of a standard Japanese loom starts from 32 hours labour +VAT. Labour is at our current hourly rate and the intial design fee applies in all cases.

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:


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.