Tuesday, 18 October 2011

XADO - Engine treatment tested and reviewed

XADO makes a lot of claims for their revitalising gels, and being inquisitive I like to test all products before agreeing to stock them at F2 Motorcycles Ltd. I am happy to admit that when I first read the claims, my initial reaction was sceptical but entertained.

The Claims.
I don’t want to just copy all the claims here so if you would like to read them in full they are on the XADO UK website which can be found here http://www.xado.co.uk/ There are more on the FAQ page and still more on the individual product descriptions.

Tuesday, 11 October 2011

Ural 750 - Tappet Adjustment

At F2 Motorcycles Ltd we still hear from people who have set their tappet gaps according to the factory handbook. They usually complain of lots of noise coming from the right hand side of the engine. So here is the F2 Motorcycles Ltd guide to setting the tappet gap.

The factory handbook instructions require the tappets to be set at top dead centre using marks on the flywheel. This system assumes that the lowest point on the camshaft is machined exactly to correspond to the position it is in when the piston is at top dead centre. A fair assumption, but unfortunately in the case of Ural it is a completely false assumption.  The method and settings we use at F2 will work on all Ural 750 OHV engines. The same method but with different settings will work on every 4-stroke engine I have ever come across.

It is so simple.

Sunday, 4 September 2011

Adjusting Ural Twin Leading Shoe Front Brakes

 Notes - Ural twin leading shoes brakes can work acceptably well if correctly adjusted.
There are square adjusters with lock nuts on the end of each brake shoe.
There is also an adjuster on the cable for fine adjustment.
The link rod on the outside of the brake plate that connects the two brake cam levers does NOT have a left hand thread in one end. This means simply turning it will not change the distance between the two brake cam levers.
However F2 Motorcycles Ltd do sell a replacement adjustment rod with left hand threads at one end.
These instructions assume you have the standard adjustment rod.

Friday, 2 September 2011

Fitting New Pistons to Ural Motorcycles

Fitting New Pistons to a Ural.

When fitting new pistons it is important to ensure that they fit the cylinders properly.
Before you start to measure anything carefully inspect the piston and gently remove any burrs from the bottom edge of the piston skirt with some 1500 grade wet and dry paper.

Sunday, 14 August 2011

Only running on one cylinder.

Several times a month I get a desperate phone call from somewhere in the world from a Ural owner wanting advice because their bike is only running on one cylinder or producing very little power. Fortunately most parts can be swapped from one side to the other. Following these instructions will establish why your bike is running on one.

Wednesday, 10 August 2011

How to Fit a Sidecar

Before fitting a sidecar check the motorcycle carefully. Any slight play in the wheel, swing arm, or steering bearings will cause low speed wobbles and will wear to a dangerous condition very quickly once the additional stress of a sidecar is added.

Take a look at the tyres, they do not need to be anything special but ideally they should be flattish on the top to get as much contact area as possible. Ribbed tyres really mess up a heavy fast combo and should never be used, if the front tyre has long lines in the tread going inline with the bike change it before the sidecar is fitted.

Fitting a sidecar, this is a rough guide only.
You will need a flat level area and plenty of time.

Monday, 8 August 2011

Wiring for standard 12N socket to Ural.

Standard towing sockets in the UK are normally the 12N type. These have 7 pins and are often numbered on the inside of the case where the wires connect

Below is a guide to wiring this standard socket to a Ural. 

Saturday, 6 August 2011

Ural Oils

Urals have a roller bearing crank and gear driven cam. This applies massive shear loads to any oil in the engine. Oil lubricates by forming a film on the surface to stop metal to metal contact. It also acts as a coolant by taking heat from the hottest parts of the engine such as the underside of the piston crown and the area around the exhaust valve and carrying this heat to the sump where it is cooled by air flow. To achieve lubrication it is vital that any long chain molecules in the oil can not be sheared (or cut up) into short chains.
As stated the cam in the Ural is gear driven and extreme pressures exist between the teeth. Roller bearings found in the crank big end of Urals which are constantly accelerating and then slowing apply huge shear loads to oil. From this you will see the oil required for the Ural must be able to withstand shear and pressure loads much greater than those found in a plain bearing crank with a chain driven cam. Monograde oils are almost impossible to shear. A straight 40 will remain a straight 40 for the life of the oil. Mineral multigrades shear very easily and at very low pressures. A mineral 20w50 multigrade will shear to a monograde 20. Once this happens metal to metal contact will occur leading to fast wear rates and a very rapid increase in spot temperatures. Semi synthetic oils have long chain viscosity improvers which withstand shear loads and keep the viscosity grading correct for a longer period of time. Fully synthetic oils are even stronger than semi synthetics and are extremely difficult to shear, they will also withstand greater pressures. EP mineral oils for gearboxes have an extreme pressure additive to cope with the high pressures found between the teeth of the gears (EP stands for extreme pressure). There are several types of viscosity improvers, the most shear stable (as used in quality brands) are referred to as type VI. The cheaper semi synthetic and even a few fully synthetics use a low cost type VII improver that does shear.