Andy Tiernan Classics Ltd - Dealers in British Motorcycles
Technical Information
Click on the subject immediately below or scroll down the page to find the information you require
BSA drop forged steel frame lugs - Amal Carburettor Needle Information - DVR2 Electronic Voltage Regulators - Ethanol Free Petrol - Ethanol In Petrol - Ignition Coils - Norton WD Big 4 & Wheel Driven Sidecar - Dynamo & Regulator Fault Diagnosis - Beaded edge tyre, rim & tube sizes - Unleaded Petrol
BSA drop forged steel frame lugs
There is a very interesting article from 'The Motor Cycle' magazine, dated May 4th 1922
Beaded edge tyres, rims & tubes sizes
Modern ignition coil problems
Over the last few years we have experienced an abnormally high failure rate with the modern ignition coils. In our recent experience the modern ignition coils (both 6 & 12 volts) currently on the market being sold for classic motorcycles, generally seem to be of low quality, only having a short working life of a few years (often 2 or 3 years).
We are bringing this to your attention because we are aware of many problems that have had people running around in circles thinking they have all kinds of carburation &/or ignition problems.
The easiest way to find out if you have an ignition coil problem, is to substitute your suspect coil for a new one or a known good one, & then see how your bike runs.
A few notes on petrol in the UK
Ethanol Free Petrol
Flat tankers
From our experience ethanol in fuel can cause problems in earlier vintage & veteran machines with soldered tanks (leaks etc.).
We endeavour to use ethanol free petrol in all our flat tankers (Aspen is our preferred petrol with the added bonus of having a long shelf life & is availble from most lawnmower businesses).
The following internet links may be of assistance: -
https://classicfuelsolutions.co.uk/
Unleaded Petrol
The first, & perhaps most important point to note is that classic motorcycles should run fine on unleaded petrol, without the need for a lead substitute additive.
Here in the UK, petrol from road side filling stations is now all unleaded, & has been for some years. When unleaded petrol was first introduced into the UK, & leaded petrol became harder to purchase, there were certain myths that started going around regarding valve seats in classic motorcycles.
It became the mission of certain interested parties to make us believe that we needed to have new 'unleaded valve' seats fitted to our classic motorcycles as soon as possible. This was & is simply not true, it is not necessary to have your valve seats changed purely on the basis of using unleaded petrol. The simplest thing to do is just to carry on using your bike as normal, & only have unleaded valve seats fitted, if & when your original valve seats wear out. In practice most people will find that their original valve seats do not wear out, & therefore do not need replacing.
Our fitter, David 'Beret' Berry (now sadly deceased), who was with us for over twenty years, clocked up hundreds of thousands of miles on a number of different British classics (he had quite a collection, & rode them daily to work, as well as on long distance touring holidays two up). He never had unleaded valve seats fitted to any of his motorcycles, & never needed them!
Ethanol in petrol
This is not good for anyone in the classic vehicle world. Modern vehicles are made to run on petrol containing ethanol. Unfortunately older classic vehicles were not.
The problems for classic bike owners include: - Fibre glass fuel tanks that go soft as the resin that binds the glass fibre together is dissolved by the Ethanol. Fuel tanks that have been sealed with a leak sealant at sometime in the past, again the ethanol dissolves this sealant. In both these cases, a sticky yellow mess results that blocks up your fuel system (petrol taps, filters, carburettors etc.
There are solutions to problems with fibre glass tanks. Replace your fibre glass tank with a steel or alloy one. Alternatively you could get a new fibre glass tank made in ethanol resistant material. You can also get one of the new ethanol resistant sealers for the inside of your tank, but the outside may still suffer if you spill any petrol on it.
The solution for old sealant inside your metal tank, that is being dissolved by the ethanol, is to get a chemical to remove the old sealant, & then to re-seal your tank with one of the new ethanol resistant sealers.
Ethanol also attacks & degrades other parts of the fuel system, such as rubber pipes & seals, as well as zinc & brass fittings.
We do not recommend any particular company or product, but here are some internet links that may be of assistance: -
http://www.frost.co.uk/automotive-car-bike-maintenance/automotive-tanks-products.html
http://www.burtonbikebits.net/ethanol-in-fuels.htm
http://www.tankcareproducts.co.uk/
http://www.cwylde.co.uk/section.php?xSec=5
http://www.hitchcocksmotorcycles.com/news/22198//Ethanol_-_Part_One:_The_Risks
A further problem with ethanol in petrol, is water. Ethanol is hygroscopic, which means it absorbs water. This in turns leads to rust & corrosion inside your petrol tank. If you use your classic motorcycle regularly this is usually more of an inconvenience than a serious problem, however if you leave your machine standing for long periods, then this problem becomes much more serious. Also petrol containing ethanol does not seem to have a very long 'shelf life', we have heard a number of incidents, where people have tried to start their engine after they have been left standing for a number of weeks; only to discover that the petrol has 'gone off', & has to be changed before the vehicle can be started.
Once again there are solutions. One solution is to use an additive for your fuel. Additives can both extend the 'life' of the petrol, where machines are left standing unused for long periods, as well as protecting against rust & corrosion forming.
Once again we do not recommend any particular products, however the following internet links may be of assistance: -
http://www.millersoils.co.uk/automotive/classic-fuel-additives.asp
http://www.halfords.com/motoring-travel/engine-oils-fluids/fuel-oil-additives
http://www.holden.co.uk/displayproduct.asp?pCode=094.170
Amal Carburettor Needle Information
Some years ago our engineer, Dave 'Beret' Berry started compiling information on Amal Carburettor needles, after struggling to find information he needed. The information was put together over a number of years, however sadly he was killed in a motorcycle accident before it was fully completed.
Click here for a .pdf file of the information
Each box has the model of carburettor, & then three items of information underneath - 1st the markings found on the needle, 2nd the number of grooves in the needle & 3rd the overall needle length.
We trust this information may be of use.
Dynamo & Regulator Fault Diagnosis & Repair
The following information was compiled by David 'Beret' Berry our late fitter, over a period of several years, based on his own experiences of fault diagnosis & repair of old dynamos & regulator boxes.
Click here for a .pdf file of the information
DVR2 Electronic Voltage Regulators
Due to recurring problems with certain makes of voltage regulators that we have fitted over the years, we decided to find one reliable make. The DVR2 electronic voltage regulator from Dynamo Regulators Ltd. proved to be the answer for us. We now have fitted dozens of these units with no problems.
The DVR2 electronic regulator will charge from a completely flat battery. They are available as postive or negative earth, 6 & 12 volts.
Website: -
https://www.dynamoregulators.com/
1940 WD Norton Big 4 633cc with wheel driven sidecar
We have just had some new sidecar wheel drive parts made to help complete this machine. This collage shows the bike, both ends of where the drive connects (at the bikes rear wheel & at the sidecar wheel) & the parts that have been made (which includes the dog clutch & operating lever). A prop shaft is needed to finish the job.
Call for details:01728 724321 - Or email:andybuysbikes@hotmail.com