Ariel technical articles

Morgo Oil Pump Brochure

All though this document is titled Square Four MK1 it does give the general information for the Morgo Oil Pumps. These are available for Ariel Singles, 4G, MKI and MKII machines. These are a must for those people who travel long distances or demand the most out of their bikes. Roger has fitted one of these to his MKII and found that the increase in pressure has resulted in there being an excess of oil coming out of the breather so he so he enlarged and extended the breather pipe to run the length of the bike. As the pipe is taken as high as possible it allows the oil to run back into the engine.

Big end assemblies
Using this list it easy to find the part number for any Ariel big end assembly from 1926 to 1965. Is a VH big end the same as an NH? It is possible to answer this question with this list.

Brake pedals
A table listing many but not all of the brake pedals used by Ariel over the years. If anyone fancies completing the list, we would be pleased to add it to the table

Burman-Ariel-Panther-AMC cross reference list
A cross reference list of Burman and Panther numbers to Ariel, which are of course the ones we use. AMC always used Burman numbers. The Panther information was supplied by one of our lovely customers Panther owner.

Chains – Length vs Sprocket Size
Find the length and size of chain required for any Ariel 1937-65 or unit BSA 1949-72. Using the sprocket sizes you will be able to determine the length you require. This is great if you have non standard sprockets and need a chain. Remember the old one you remove may not be the correct one since it could have been shortened to take up any slack. All available at competitive prices from Draganfly.

Engine and Frame Numbers
It is essential to know the exact model and year of your machine, not only to restore it accurately but simply to increase the chances of obtaining the correct parts. With a Vehicle Identification Number (VIN) in your hand anything is possible; you would be surprised at how many people believe that their bike is something different to what it really is. Don’t necessarily go on what the registration document states, since this could be incorrect. If you own a two stroke remember that the frame and engine number should be identical. The listing includes gearbox numbers. Don’t forget people that can make their own VIN plates so this could also be wrong.

As the title suggests this is a mind boggling list of all the screws, bolts and studs that we stock, complete with diameters, lengths and head types. So if you are looking for a fastening by size here is the answer, if you know the application it is usually easier to look it up in the catalogue or parts book.

Flywheel Numbers – Now there’s Fun
A table to translate the casting numbers on the flywheels and con-rods to proper part numbers complete with applications. This was written by Roger and shows his dedication to the subject and the job. If you are able to find other motorcycle websites with such detail I will be surprised, eBay doesn’t give you this level of care or attention.

Full width hubs BSA-Ariel
Which bits do you have to change to fit the BSA version of the Ariel full width hubs to an Ariel? What, I hear you cry, are they not the same?

Gasket set
Just what goes into our gasket sets, the answer is here plus of course a lot of research many years ago.

Petrol taps – a guide
If you were wondering which petrol tap to buy, here is a guide. How to measure your old tap, do they have filters, what about a reserve etc?

Piston to bore clearances
How much room should there be between the piston and bore? Too much and it will rattle, not enough and it may seize, it may seize anyway but here are the official figures. Modern pistons use the same figures as the modern alloy expands at the same rate as the old stuff.

Pistons and Rings
Another huge and comprehensive list; this time all the sizes and details of every piston, ring and gudgeon pin along with OE, Hepolite and Wellworthy numbers that could be found.

Plugs, Points, Batteries, etc
Here is a list of the electrical components used on Ariels and BSA bikes. By giving us the part numbers from this list you will not only save your telephone bill but also ensure that you receive the correct part.

Rims and spokes
This is the table that we use to find the part numbers for rims and spokes, it includes a listing of ‘wheel types’. Have you ever wondered if all rims are the same, using this table you can find out? Roger spent about 50 hours compiling this and does not want to look and rims and spokes again for a long time.

Sloper survey
A friend asked if I could tell him how many Slopers went to Germany. I got carried away and listed all of them from 1931. One for people who really cannot sleep.

Toolboxes and fittings
Toolbox fittings are frequently ignored in the parts books, here is all the known information on plunger and rigid toolboxes from 1929 onwards. Information mainly compiled by Bruce Longman.

Transfer Listing
This is a detailed listing of transfers used from 1910 onwards and is accurate as Roger can make it mainly using information compiled by Jerry Mortimore of the Ariel owner’s Club. The listing is broken down into application by model and details of each transfer.

Valve Dimensions
Table listing the main dimensions of all Ariel and BSA valves that we have data for. As it is in Excell the table can be ordered on any of the parameters or filtered to show certain criteria.

WNG contract details
Details, as far as is known, of all the military production between 1939 and 1945, not just W/NG and other models for the government but civilian production, as well. Complete with cross references between engine numbers, frame numbers and contract numbers. Information from my own research, Ralph Hawkins and British Forces Motorcycles by Madden and Orchard; an excellent book for any military enthusiast.

Petrol taps
This is a great document with all of our taps including the sizes, use it to work out which style and size you require.

Fitting transfers instruction sheet
So you have bought some transfers from us and you have lost the sheet. Or perhaps you would like to read all about it before you stick the Horse to your arm? Please do remember that although we try and list which transfers use which fitting method the suppliers keep changing the type. This is why we have put details of each type so you can look at the transfers and determine if it is in fact ‘waterslide’ or ‘rub on’ Good Luck.

Fitting a Replacement Clutch Chain Wheel to 1936-58 Ariel
Using a large hammer and a punch, or a press, knock out the pins that retain the old chain wheel to the centre boss. In order to line up the new chain wheel, fit some longer than standard ¼ CEI bolts through the boss into the chain wheel and press the boss into position. The dowel holes should then be drilled through from the boss side with a 7mm drill. Finally press the dowels in.

White wall tyre fitting
Details on fitting said white wall tyre trims. Do read these instructions carefully before undertaking this task. Since these trims are not cheap it is worth doing this on a day where you are calm and have plenty of time. Do not rush it and you get the great finish you want. We offer these since we can not find a supplier for white wall tyres, “at Draganfly we would if we could”.

Carburettor Sleeving
Poor starting and erratic tickover is usually caused by wear between the throttle valve and the body. Fitting a new slide in a worn body is like fitting a new chain to old sprockets, a waste of time. Wear is likely to be apparent as early as 5,000 miles, but can be rectified by boring the body oversize and fitting a sleeve to the slide. The materials used in this process will last a lot longer than the original. This is preferable to fitting a non-original later type of concentric carburetter. The new carburettors that are now available have improved materials but are not as good as a sleeved one. The price for re-sleeving on its’ own is to be found under part number RES169, for this all we need is the body and slide. Alternatively, send the complete carb to us and we will replace other worn, missing or damaged parts, check threads, re-plate the fittings, peen the body parts and re-assemble for an approximate price please click here. We cannot sleeve the Concentric range but we can supply new ones at very competitive prices.

Electronic Regulators
It is nowadays very difficult to find an original mechanical regulator box in good condition and the only replacements are the type for the 40 Watt dynamo and are made in India. The answer is to replace it with a modern electronic one, that, providing the instructions are followed will provide many years of trouble free use, indeed members of staff have covered more than 50,000 miles without trouble. These electronic marvels are small enough to fit inside the old regulator and are therefore undetectable in use. The units come complete with comprehensive instructions but as the instructions point out a new regulator will not fix dodgy wiring or a duff dynamo! If converting to 12 volts the battery and bulbs will need to be replaced but the horn should be OK as long as it is not operated for extended periods! Due to the higher voltages involved the dynamo will not cut in as early as it will with 12 volts, typically it will not be charging at 30 m.p.h. in top gear, especially if the gearing has been raised and this is a real problem on the SQ4 especially so because the ignition system relies upon the battery. Unless the bike is to be used a lot after dark or high mileages are expected a 12 volt conversion is probably not worth the trouble, a 6 volt system is perfectly adequate providing the connections are maintained in good condition. If a 12 volt conversion is tried and charging is a problem a 12 volt armature and field coil will lower the revs at which the dynamo will commence to charge and this does work well, although not available for the SQ4. Also when converting to 12 volts the largest battery that can be fitted should be used as the dynamo can be destroyed by using a small battery as I found out to my cost at 4 o’clock in the morning in the middle of France. These are the only regulators that we have found that will work with the large Square Four dynamo. ELE-29 +ve earth  -ELE-28 -ve earth Each unit can be used as a 6 or 12 volt unit.

Types of Oil
On the subject of oil, we recommend that engines with roller bearing big ends are run on monograde oils i.e. single viscosity sae 40 in winter and sae 50 in summer. This is because this type of oil can withstand the high loads experienced in a roller bearing big end where all the force is through just one or two rollers. Monograde oils should not be confused with ‘straight’ oils, which means oil without additives. The principal additive in modern oils is a detergent that is used to keep deposits in suspension until they reach the oil filter. They will also loosen existing deposits and as there is no effective filter this can be disastrous in an engine that is full of ‘gunge’ accumulated over the years. Engines with shell bearing big ends can use either a monograde or a modern multi-grade oil. The multi-grade oil will lubricate the shells more quickly when the engine is first started which is when most of the wear takes place and so is more suitable for short journeys; it is also cheaper and more easily obtainable. Monograde oil will leak less; the engine will run cooler and quieter, is available as a straight oil and is more original!

Fitting of mudguards
Information and fitting instructions for these mudguards including details of stays. Much work has gone into this and since Ariel were not the best of companies to keep details of changes so there can be techniques for fitting and also choosing which mudguard you require.

Electronic ignition systems – a guide
This article discusses the pro and cons of fitting electronic ignition in both a practical and a philosophical sense. It also lists the types of kits available and what is in each kit. The all important part numbers are included should you be tempted to buy one!

Not all Ariels are Red Hunters
This is an introductory article covering the Ariel model range including a guide to the model codes used by Ariel. It can be used to find the proper code for your bike, and why calling all singles ‘Red Hunters’ is not very accurate.

Real Classics Article on an Arrow
Ariel’s Arrow was certainly an oddity, and it is most definitely an old British bike. But is it a genuine classic motorcycle? Paul Friday doesn’t really care, because his Arrow was certainly the worst bike he’s ever owned…

The Cammy Rally Held in Spain
Take many old men, several Square Fours and a long trip to Northern Spain. The result is an article in German detailing the entire fiasco. I can’t really say a great deal about this article since it is in German. If there are any of our beloved customers who speak German and would like to translate this into English then that would be great. Photos & Article Copyright – Markus Nikot.

Amal type 6 tuning
Standard Amal type 6 (old leaky, remote float) carburettor tuning document but re-written and re-drawn in a clear manner. I stole this from somewhere but cannot remember where, sorry. I don’t remember doing it but I might have done.

Balance factors
Some information on balance factors on the Ariel singles from Roger Slater of Laverda Jota fame who now lives in Washington State in the USA where my hero Jimi Hendrix came from.

GB gearbox mainshaft lengths
How long should my mainshaft be? Long enough is the answer.

Sidecar article
If you are fitting a sidecar this excellent article will tell you not only how much lean out to use but how to cure poor handling outfits.

Singles camshaft lubrication modification
A well known modification to raise the oil level in the cam chest of Ariel singles to reduce cam wear as the factory did for the Scramblers.

SQ4 overheating and oil coolers
Have you bought a square four and feel it is overheating, your friends have told you to ‘slap an oil cooler’ on the machine. Well if you would like to save time, money and blood then I recommend you read this article since it will help you more than ‘Old Bob’ at the pub. Granted it won’t buy you a beer though.

SQ4 Valve Timing
This is an article from the ‘saviour’ of the Square Four, Bruce Longman. It covers the differences between cams, how to identify them, what happens if an early cam is fitted to a late engine and most importantly how to get the timing right.

Carburetter Settings
This is a list of carb settings for all Ariel motorcycles.

Burman Gearbox Ratios
A useful table of gearbox ratios for those wanting to alter the gearing on their machine. This is not an exhaustive list!

Wet Sumping & Oil Pumps
When the oil in the oil tank drains into the sump and fills the crankcase it will cause the machine to smoke a lot and to pump oil out of the breathers until it is pumped back to the oil tank, this is known as wet sumping. All gear type oil pumps will do this to a greater or lesser extent, even when new.