General Information

Bike (850 Commando) has been rebuilt and ran great for about 20 miles until plugs sooted up. Put in new plugs and same thing happened. Customer thinks it is an electrical problem (has Boyer ignition) trashing the plugs.

It sounds more like a mixture problem to me and this should be checked first. Check you have correct 850 Commando carbs with the “cut away” at the front of the spray tubes. Needles should be the special long ones (2.765″ long) and not the regular 928-932 type (2.69″). Needle jets should be the type with the little holes in the sides..106 size.

Needle jets can wear fast (especially in the Commando) and often need changing after only 8-10,000 miles. Worn needle jets will cause the problem described.

Other things to look at – restricted/dirty air filter element, choke lever screw coming loose allowing slide to drop down, incorrect cam timing (bike will still run of you are one tooth out but won’t breath as well)


Silly Questions (Actually the silly one is the one that isn’t asked)

The intention here is not to embarrass anyone but we frequently get these questions. We receive literally hundreds of enquiries every day. We can’t hire anyone with detailed mechanical knowledge of the whole range of British bikes who can get into lengthy discussions with customers, especially those who are new the the pastime, giving detailed advice on how to restore/rebuild & repair their bikes.

Motorcycles can be very dangerous if not assembled correctly with the correct parts. Every customer working on his bike must know the limits of his ability and be prepared to take it to a fully qualified mechanic where necessary.

Many of the questions we are asked are covered in full detail in the original workshop manual. It is absolutely essential essential that anyone working on a bike has access to the correct workshop manual and parts book for the machine. The latter is very important because it has detailed assembly diagrams and very often enables the customer to ascertain that the previous owner had fitted incorrect parts.

There are experts available in most of the single marque owners’ clubs who are willing and able to help other members. Posting a question on an internet discussion group can be very dangerous – many of the “experts” giving advice have not got a clue what they are talking about. There are also some very knowledgeable capable contributors – you have to know where the advice is coming from. I know G/N15 Norton.Matchless hybrids and P11′s pretty well and some of the information I see on these bikes it terribly wrong.

Q I have spent a lot of money restoring this bike with parts from Walridge Motors Lmited and it now only runs on one cylinder. Please tell me what is wrong.

A. I could write a book to help this guy determing the answer (in fact Bernie Nicholson did) but he needs to take it to a mechanic who can run siome tests. Very difficult/almost impossible to answer over the telephone.

Q Will the A65 BSA pistons you have on sale fit my Triumph Bonneville.

A. Not without a lot of modification

Q The electric clutch on my 1969 Bonneville turns the motor off when I pull in the clutch lever.

A After a mechanic looked at this bike, belonging to a licenced electrician, it was determined that he had fitted a Boyer kit himself but had left one of the electrical connection exposed without insulation. This connection was being flexed upwards by the clutch cable when operated and grounded to the frame.

Q Control cables and wheel rims/spoke sets which “don’t fit” represent 50% of the technical questions and are covered elsewhere in the help and advice section.


Oil Pressure Guage Thoughts

We are frequently asked for price and availability on these.

While several types have been available over the years, I find they are a bit of a waste of time. The most common mechanical failure in British twins is where the sludge trap in the crank gets blocked, the L/H big end seizes and the left rod does a number on the left crankcase. I have planty of evidence at the back of the shop in the scrap aluminum pile if anyone doesn’t believe me. There’s no easy way of measuring the oil pressure at the L/H big end so the main thing is to clean the sludge trap well on an engine rebuild and then subsequently use a detergent oil with an oil filter in the return line. Also, oil pressure gauges with a copper line up to a gauge beside the speedo is an accident waiting to happen – vibration is guaranteed to fracture the line eventually which could lead to catastrophic results if not noticed in time. I recommend the oil level and circulation be checked before every ride.


How many Seeley Condor’s were made?

I had the great pleasure of meeting Colin Seeley at the recent Stafford Classic Bike Show and he told me only 7 were actually made. I also congratulated him on his incredible achievement in producing two remarkable books “Colin Seeley Racer….and the rest” and “Colin Seeley…and the rest”. These beautiful books not only document Colin’s illustrious career but are full of insight into Grand Prix and motorcycle racing in general through the 1960′s right up to the present time. I guarantee that anyone with even the slightest interest in the racing scene will have a hard time putting these books down once they’ve started reading them and the illustrations are incredible. At $59.95 each they are superb value and if anyone talks to me nicely I’d do the pair for $100.00 while stocks last!


Part Numbers on Parts

Don’t assume the part numbers appearing on parts are correct, they are usually casting numbers and the actual part numbers will be slightly different. For example there’s quite a number of different Triumph side stands all with the same number on the side. The only exception appears to be Lucas parts which usually have the correct part number actually on them.


Complete Tool Kits By Part Number

We are frequently asked to quote on complete tool kits by the part number in a parts book.

Regret we don’t have a source on these and when they come up on ebay they usually go for high prices.

We do list tool pouches and rolls however the individual tools are best sourced by their individual parts numbers. We can come up with some of the tools and if a customer wants to make the effort to search around the rest could probably be found eventually.


Motorcycle Restoration Correctness

I don’t get hung up about this at all and if someone owns a bike they can do what they like to it. Forty or fifty years ago we used to customize or change our bikes to suit ourselves, just as people do now, and never thought “experts” would get into heated arguments many years later about details. I had a new 1966 T100SS, rode it home from the dealers cut the horrible light grey grips off and threw them in the garbage. The guys I rode with wouldn’t been seen dead with someone who had those “pretty” grips on his bike. Now restorers become anal about finding these correct grips! The only measure of what’s correct is to look at a period road test or a picture of the first owner taking delivery. Sales brochures were printed months before the bikes were made and detail changes were made in the ensuing period. Even the 1967 Norton/Matchless G/N15CS factory brochures state “fitted with coil ignition and concentric carbs” and the bikes in the pictures have monoblocs and magnetos. Restorers “must” have the Queen’s Awared for Industry decals on their Triumphs because they have seen them in pictures, however I understand this decal actually only went on UK home market machines. Then again, it could be a bike which was originally purchased in the UK. Some late 1970 Bonnevilles came from the factory with the 1971/2 type megaphnoe mufflers, try getting this past a judge at the concours. A few 1973 750 Commandos had 16″ rear rims fitted in the USA before they were sold new to the customer. Importers could go to the factory and make special requests for specifications on batches of bikes they were buying. I once took a brand new Silver Jubilee, never started, guaranteed original, to one of Jerry Wood’s auctions. Quite a number of “experts” told me it was a very good restoration and pointed out all the things which were not correct!


Applying Press and Stick Decals

The best type are the press and stick ones where you apply the decal, sticky side down to the bike, rub the back of the release paper firmly and then gently lift of the release paper. Most original decals were applied this way. Dealers, including us I regret, often find that after these decals have been on the shelf for several years, the sticky surface on the backs of the decals themsleves becomes virtually or totally non existant. Rick Harrett of Highway Cycle near Hamilton, Ontario came up with the following solution. Paint a thin even film of Elmers Rubber Cement on the back of the decal then press it firmly into place, leave it overnight then gently lift off the release paper. I was a bit sceptical about this but decided to try it on the dryest decal I could find and was pleased to find it works! Any cement residue can be carefully cleaned up with a moist cloth. I found scotch taping one side of the release paper helped with holding the decal in position while rubbing the back firmly to remove any air bubbles.


What make of levers were used on my 1961 Matchless?

As far as I am aware, Amal made the levers for most British bikes, including Matchless. The Amal reproductions from the Orient are generally of barely adequate quality however the Doherty UK made reproductions are much nicer and seem to be the preferred choice. The biggest complaint about Doherty levers, used on some Royal Enfield and other makes, has been that the pivot to cable nipple distance of 1 1/8″, while giving a longer pull, does not give the same degree of leverage as the Amal 7/8″ distance. Doherty now also make levers with the 7/8″ distance however not yet for all the complete range, please call with specific requirements.


General Restoration Help and Advice

Customer wanted a quote on a long list of hardware for an earlier Matchless he was restoring. After searching through numerous wholesalers’ catalogues we were able to find listings and quote on almost all of it. He then wanted up to be sure the finish on all the parts would be consistent for his restoration. This isn’t possible, even NOS stuff from the same manufacturer in the same year varies – some of the cad plating can be quite shiny, some dull grey and some yellowish. I remember an article several years ago by Robin James. Some points he made stuck in my mind. Firstly “restoring” really means to me re-creating the bike the way it left the factory. These were not works of art lovingly created by caring craftsmen, they were means of transportation, built down to a price and were only lucky to get out of the factories if none of the numerous unions were on strike. Work at the factories, I am told, pretty well stopped on Wednesdays when Motorcycle News came out. The work week was Monday, Tuesday, Motorcycle News day(or sometimes called dumpa dolly day), Thursday, Friday!

Back to restoring. First order up all the parts and assemble the bike completely. Make sure everything fits, lines up and works properly. Then completely disassemble it and get everything painted, plated, polished. Send all the fasteners to one place and get them plated in one batch. I get quite a number of complaints from people that parts don’t fit quite right, after they have had them painted etc. These bikes were not precision engineered and no two are exactly the same so a certain amount of tweaking and modification if often required.


British Motorcycle Colour Schemes

We are asked on an almost daily basis to supply information re paint codes and layups for British motorcycles, especially Triumphs. While I can help with the later Matchless and Norton/Matchless hybrids I prefer to refer enquiries on Triumphs to Don Hutchinson who is the expert on this subject It is not legal to mail paint across the border so Canadian customers have to find someone in the USA who lives close for Don to ship to.


Speedo and Tach Quick Facts

Some quick facts on instruments: if your speedo drive is stamped 15:12 or 1.25:1, the face of your instrument should read 1000 – ie the cable will sping 1000 times per mile. Should read 600 if the instrument is calibrated in kms. If your drive is stamped 2:1 the cable will spin 1600 times per mile so this number needs to appear on the face of the instrument. Most tachs are marked 4:1 (eg late Triumph twins) although Norton twins with the drive on timing cover be 2:1 or 4:1, so the appropriate drive box has to be used. BSA A50 & A65′s use a 3:1 ratio tach.


Preventing Speedo and Tach Failure

Magnetic Smith’s instruments (mostly 1964 onwards, grey faces to 1969, black thereafter) failures are caused by one of two things. Firstly, vibration – they were really not robust enough in design, which is probably why Smith’s at one time only put a 3 month warranty on them. Secondly, improper fitting. We have had several failures where the cable has pushed up into the instrument too far and destroyed the mechanism. If you hold the nut in the highest position before scrweing onto the bottom of the instrument, the end of the inner cable should be level with the top face of the nut. Any higher you have a problem which needs to be investigated.


Preparing Your Motorcycle For Winter

We are frequently asked for advice on this, although it is covered in most of the handbooks.


1. Clean and polish bike throughly.

2. If steel gas tank, fill it completely and add fuel stabalizer*

3 Start motor and run to operating temperature

4 Empty oil and change/clean oil filter as appropriate

5 Fill with clean oil and check for circulation and no leaks.

6 Turn off gas and drain carbs

7 Remove plug/s and pour a couple of ounces of oil down the plug holes

8 Kick motor over a few times to coat the cylinder walls

9 Replace plugs

10 Remove battery and place it on a bench – NOT on a concrete floor, in a heated area. Arrange to trickle charge the battery every month or so. Check specific gravity with a hydrometer or better still leave a Battery Tender (type which maintains full charge) connected.

11 Store bike in as dry as possible place with a soft cover over it – nice if you can get the weight off the tires.


* I like to empty plastc, aluminum and fiberglass tanks.



BSA Motors Stamped with a ‘Y’

I have asked many BSA experts about this over the years and have never been able to find the right answer. Following research by Harris Turner (USA) and Brian Pollitt (Lightning Spares, UK) the mystery has been solved. It was originally rumoured that it related to unsold new bikes which had been kept at the factory because they couldn’t sell them due to unfavourable exchange rates. The “Y” was said to indicate to dealers that while the bikes might be 2-3 years old they could still honour warranties. I know the practice of storing unsold bikes was quite common at that time, especially with AMC, the real reason for the “Y” is as follows. During 1967 the alternator was updated and the zener diode with it’s heat sink moved to the front of the bike. The “Y” was stamped on these bikes to indicate that they would need different wiring harnesses. Who would have thought back then that this would be the subject of debate 40 years later!


Quick Guide To BSA Dating

We are only detailing here the bikes we most often come into contact with. The owners’ clubs and various restoration books provide more detailed advice.

500 & 650 Twins

Up to and including 1966 the engine and frame numbers did not match so you will have to go back to the original records to confirm the authenticity of a machine.

For 1966, all frame numbers ran from A50C-101 and up for both 500 &650cc machines.

The various models were distinguished by their engine numbers. Each one had a prefix for the model followed by a sequential number starting at 101 for the particular model.

500 Royal Star used A50R and the Wasp A50W.

650CC Models would be A65T for the Thunderbolt, A65L for the Lightning, A65H for the Hornet and A65s for the Spitfire.

From 1967 onwards the engine and frame numbers were the same for all these machines when they left the factory. The numbers followed the engine number designations used in 1966, adding a letter code to the serial number. For the 1967 the letter “A” was used, “B” for the 1968 and “C” for the 1969.

For example, if you have a bike with the motor and frame number A65LB-11256, it will be a 1968 Lightning. Part way through 1969 it was decided to change this system and use the system which was also adopted by Triumph and is shown below.


Quick Guide To Triumph Dating

We are only detailing here the bikes we most often come into contact with. The owners’ clubs and various restoration books provide more detailed advice.

Engine and frame numbers always match for the following bikes and others for the years listed below. They also matched for many years prior to these bikes.

These are the first machines for the model years listed.

Unit Construction 500 Twins Unit Construction 650 Twins
1966H40528 DU24875
1967H49833 DU44394
1968H57083 DU66246
1969H65573 DU85904

As with BSA, part way through 1969 the new system was adopted for all models, as follows:

Month of Manufacture Model Year
AJanuary C1969
BFebruary D1970
CMarch E1971
DApril G1972
EMay H1973
GJune J1974
HJuly K1975
JAugust N1976
KSeptember P1977
NOctober X1978
PNovember A1979
XDecember B1980

** Please note that production for any particular year started in August of the preceding year. If, for example, you have a machine with “JD” in the serial number, it is a 1970 model but was actually manufactured in August 1969. For correct parts for this bike you would use the 1970 parts book.


Quick Guide to Norton Dating

We are only detailing here the bikes we most often come into contact with. The owners’ clubs and various restoration books provide more detailed advice.

Matchless and AJS 750 twins were included in the same sequential numbering system as Norton models from 1964. Norton featherbed machines (Atlas and 650 twins) had the model pre-fix in front of the of the 6 digit serial number on both the engine and frame. The other models (e.g. G15, N15, 33 & P11) had the model designation on the motor, followed by the 6 digit number but only the latter was stamped on the frame. Norton engines with “P” at the end of the serial number were made in the Matchless factory in Plumstead, London. The following is only a guide as there is some disagreement about the exact numbering system for Norton models.

Year Beginning of Number
1964 107900
1965 112000
1966 115871
1967 119760
1968 124370
1969 130021
1970 134700
First Commando 123666
First 850 300000
First Mk3 325001


British Motorcycle Terminology

Cotton: When we send you a rim marked “Cotton” it doesn’t mean we’ve sent the wrong one for your Triumph or early Matchless or Norton. It refers to the rim being drilled to suit a cotton reel type hub.

F/W: When we send you a rear wheel rim marked “F/W” we have not usually screwed up, the term stands for “Full Width hub” not front wheel.

Washer: Gaskets are often called “washers” (short for joint washer) in the UK parts books – causes some confusion.


How do I stick Triumph Knee Grips on my tank?

I do believe there was a product called “Triumph Glue” at one time however I find a modern contact adhesive works fine now. Suggest you test the adhesive on a paint surface (say under ther tank) first – there are so many new paints and clear coats in use, you weant to test for a reaction first.