Monday, 3 December 2018

Restoring Plastic Headlights

Plastic headlights on modern cars tend to fade to yellow and become very milky over time. Milky yellow lights are much dimmer than clear new lights, but because this happens over a long time most owners don't notice the lights getting worse.

Picture of light before restoration

You need to be brave to tackle this as the lights are going to look a whole lot worse before they look better. If you are brave it's fairly easy to make a huge improvement to the lights in less than 2 hours even without power tools. There are some disadvantages, and I'll mention this later.

The aim is to completely remove the original degraded factory coating, there is just one way to do this and it seems extreme. Sand it off.

Mask round the light so you don't damage the paint, I used insulating tape. BUT wax polish the paint first so the tape does not lift the lacquer when it's removed (yes I learnt this the hard way).

Use 600 grade wet and dry and use it wet with slightly soapy water, no power tools, just round and round, back and forth until the whole light is evenly matt.

Move on to 1500 grade wet and dry, and again use it wet until the whole light is smooth but still matt

Picture of light after sanding with 600

The next bit is easier with a 50mm finishing sponge and a low speed drill, but I have done them by hand, it just takes longer. Use G3 finishing compound (from a car paint shop) and polish the light until is is clear and all the matt finish from the 1500 appears to be gone. It will now look pretty good but just a tiny bit dull or matt.

Use T-cut or similar super fine cutting compound in the same way as you did the G3, and then finally use a high quality war polish to protect the surface.

The lights will look pretty much like new, and the first time you drive in the dark you will amazed at how much better they are.

Light after polishing

Now the disadvantage. The original coating was put on the light by the factory to stop the plastic getting dirty as the surface of the plastic is slightly porous. The coating has gone, you have no protection, so you will have to clean the lights far more often. A good wax polish seems to offer good protection for many weeks.

Friday, 31 March 2017

When is an EGR valve Not an EGR valve

When is an EGR valve not an EGR valve.

Just so you know EGR valves send some of the exhaust gas to the air box hence their name “Exhaust Gas Recirculation”. They are generally fitted to large diesel cars.

If you look at nearly any carburettor equipped 125cc engined motorcycles made between about 2000 and 2016 you will see some pipe work routed to the exhaust port or even into the exhaust directly, but very close to the exhaust valve. On just about every forum and facebook page concerned with these bikes you will find all sorts of complete nonsense about blocking the so called EGR valve and how it makes the bike go better, run sweeter and start better. There are even dealers selling EGR blanking kits for these 125s on eBay and similar sites. Read on, I have news for you.

They are NOT EGR valves, they have nothing whatsoever to do with recirculating exhaust gas, they do not dilute your inlet air by sending exhaust gas to the air box, they do not change the performance of your bike, blocking them will in nearly all cases not produce any increase in performance, and it may well damage the expensive catalytic converter in your exhaust.

So what are these valve things on 125cc motorcycles ?
They are Secondary Air Injection (SAI) valves also known as Supplementary Air Systems (SAS).
More accurately as there is no pump in the system they are Aspirated Air Injection (AAI) valves.

So what are they ?
They are a simple diaphragm operated one way valve.
At idle (or tickover) with the throttle shut there is considerable inlet manifold pressure and the valve is open in one direction only. Fresh, oxygen rich air can flow from the air box to the exhaust, but never from the exhaust to the air box.
When there is little or no vacuum created in the inlet manifold for example when running flat out on a flat road with a wide open throttle the valve is closed, now air can pass through it and it may as well not be there.
Under hard acceleration there is little or no vacuum in the inlet and again the valve is closed and doing nothing.
Coming down a hill with the throttle shut using the engine to brake there is a huge amount of inlet pressure, the valve is open and just like at idle air can flow in one direction only from the air box to the exhaust.

What are they for ?
In order to pass tighter emission standards manufacturers of small bikes started fitting catalytic converters to the exhaust on carburettor equipped bikes. But this created a new problem, the catalytic converters would become blocked or contaminated very quickly reducing performance and increasing emissions. By bleeding fresh, oxygen rich air into the exhaust the excess fuel leaving the exhaust could be burnt off before it got to the catalytic converter. However a one way valve was needed to make sure the air only entered the exhaust and only at times when there was repetitively little exhaust pressure such as at idle and closing the throttle to slow down. That's it, it is just a one way valve designed to give your catalytic converter a longer life.

Removing them and blanking them improves performance, right ?
No, not at all, not in any way.
They are closed and doing nothing when you accelerate.
They are closed and doing nothing when you are flat out.
They help keep the exhaust system clean when you are at idle and slowing down.

Are there any reasons to remove them ?
They are ugly , so this might be a reason to remove them.  However if the exhaust is standard and it has a catalytic converter fitted removing the AAI will almost certainly reduce performance after a short time. If the exhaust is being changed to an after market system with no catalytic converter it would be safe to remove the valve and blank off the hole in the exhaust port but only as a cosmetic measure. Removing the valve will make not a drop of difference to the performance.

They can also be problematic, if the valve fails where the vacuum from the inlet manifold opens and closes the valve there can be too much air entering the manifold from the air box making the mixture very weak. If the one way part of the valve fails exhaust gas can indeed be sent to the air box causing all sorts of running issues, melted pipe work or even a melted air box, so again this is a good reason to remove it along with the catalytic converter.

On some bikes (I only know of one) they are always on, there is no link to inlet vacuum and they flow air from the air box into the exhaust even under acceleration and flat out. These can remove so much air from the air box that there is not enough left for the engine leading to very rich running. These should certainly be removed or restricted to flow less air.

A general note about catalytic converters.
Any condition that causes abnormally high levels of unburned hydrocarbons—raw or partially burnt fuel—to reach the converter will tend to significantly elevate its temperature, bringing the risk of a meltdown of the substrate and resultant catalytic deactivation and severe exhaust restriction, hence the addition on extra air to react with the unburned fuel before it reaches the catalytic converter
But your bike may not have one.  The manufacturers or importers should be able to say if your bike has a catalytic converter. The cheapest and simplest catalytic converters are mounted in the front pipe before the silencer, it's normally easy to spot these as the pipe will increase in diameter slightly just before the silencer and it will look obviously like something had been added. However they can also be hidden in the silencer itself which makes them impossible to see from the outside.

Wednesday, 21 December 2016

XCP Rust Blocker V ACF50 testing and review.

XCP Rust Blocker is marketed as better than ACF50 along with various pictures on their site showing the results of testing to prove it is better. I have used ACF50 for years in the workshop so I'm obviously interested in anything that claims to be even better.

The first problem is the testing procedure used by XCP. I spent many years of my life working in product development specifically in the surface coating industry so I am very familiar with this test and I understand its short comings. Briefly the test sprays a 5% salt solution at the sample every 3 minutes, it never dries and it never exceeds 5% salt. I don't know many people who can ensure that the bike is rinsed well enough to reduce the salt to 5% or under every time they get off the bike and I don't know anyone at all who rides continuously in a 5% solution for a week at a time.
In the real world bikes get used on the road, they get coated in a salty solution and then parked up where the water evaporates leaving the salt as crystals on the surface. The bike than gets used again and even if the roads have not been salted again any damp or water will combine with the salt already on the bike and form a saturated solution. Then the bike will be parked up again and may or may not dry depending on where it is parked. The process will be repeated for weeks at a time. It is fair to say that just because something can with stand 5% continuous spray does not mean it can protect against stronger solutions, crystallised salt and continuous wet/dry cycling.

My test is as follows.
Apply saturated salt solution using a fine mist, to a sample which is flat so the water sits on the surface, then leave to dry for 24 hours, apply again, repeat, occasionally swap to straight water, again allow to dry, repeat. This test mimics what really happens when you ride your pride and joy in the winter and don't have time to thoroughly rinse off all the salt every time you park it up.

Two British Standard samples of fresh steel were degreased thoroughly and only handled with gloves to avoid any transfer of oils from my skin.
Both samples were then divided into two using tape.
The right hand side was treated with XCP Rust Blocker and the left side treated with ACF50.
The tape was then removed as a control area as it had no treatment of any product.
I used two samples to give the fairest results.
The first sample was treated with a much heavier coat of the product than the manufactures claim is required.
The second sample was treated with a light coat of the products as specified by the manufacturers. 
ACF50 does not dry and XCP seem a little vague about the exact drying time, so both test samples were left for 14 days to dry. Any product that claims to dry, should be dry after 2 weeks.

Both samples were placed on a flat surface and sprayed as follows
Day 1 = The samples were sprayed with saturated salt solution and left to dry for 24 hours
Days 2 to 7 this was repeated daily
This test should give an indication of the protection offered if you were to ride your bike everyday on salted damp or wet roads and then park it up after each ride.

Day 8 to 10 = The samples where sprayed in water with no salt once a day.
This should give an indication of the protection offered if you were to continue to ride your bike without rinsing the salt crystals off in damp or wet conditions

Day 11 to 18 = The samples were sprayed in saturated salt solution once a day.
This should give an indication of the protection offered if the roads are salted every couple of weeks and you continue to ride your bike everyday without rinsing or cleaning between rides.

I understand there may be a number of issues with my test method, just as there are with the British Standard salt water spray method. This is one test done in isolation and the makers of XCP dispute my results. I have no reason to fabricate results, I do not get paid by either company. I am not stating that any claim made by either manufacturer is either true or false. You can see the results and you can decide which product you wish to use. 

Thursday, 13 February 2014

Guide to Modern Ethanol Blended Fuels. E10

Guide to Modern Fuels Including Ethanol Blends (E10)

Petrol just isn't what it was in the “good old days”.

First they took away the lead, then the octane reduced over time and finally they added ethanol.

It's fair to say that fuel has changed a great deal, but unfortunately the requirements a internal combustion engine hasn't changed that much.

Higher octane always did and always will produce more power spread over more time when it burns.
Lead always did and always will protect valves from the impact they receive when they hit the seat.

100 % petrol always did and always will resist water uptake and stay in specification longer than ethanol blends.


The lead issues have for the best part found solutions. None of the solutions are as good as lead, but most offer a compromise we are happy to live with in order to save poisoning the next generation with lead fumes as we drive.

If you buy a reasonably modern vehicle it will have harden valve seats, and run on unleaded, Yes it will sound harsh at idle as lots of very hard bits of metal smash against each other in an attempt to let gases in and out of the combustion chamber many times a second.

If your vehicle is slightly older you can have hardened valve seats fitted to the head or run one of the many not quite as good a lead additives to protect your engine. If you keep the engine speed below 4000 rpm and don't overload it by towing, racing etcetera most of the additives will provide adequate protection.


The lowering of octane over time is also fairly easy to deal with as long as you don't mine burning more fuel and sacrificing a little power. A run of the mill engine with a moderate compression ratio will tolerate standard unleaded without any changes. Power will be down slightly and fuel consumption will be up a little. Higher compression engines may benefit from the rather expensive premium higher octane petrol, or the addition of an octane booster. If the vehicle has modern electronic ECU with a knock sensor the clever module will sense the very first signs of knock (pinging) and retard the ignition saving your engine from catastrophic failure. If it doesn't have modern knock sensors but was originally designed to run on a higher octane fuel, it may well be a good idea to retard the ignition slightly if you're running standard grade unleaded with no additives.


For some time now the UK government has allowed ethanol to be added to our petrol at the rate of up to 5%, from 2013 this was increased to 10%. These fuels are not labelled (E10) to warn drivers of the ethanol content, so it is not easy to avoid filling a tank with fuel containing up to 10% ethanol. There is a general belief that high octane premium fuels do not have ethanol, but this can not be proved as it is not labelled, so again it is not possible to tell.

There is lots written on the world wide web about the doom and gloom of E10 and above fuels. To be honest at F2 Motorcycles we took all this with a pinch of salt and thought it would all be OK. However from 1998 to 2013 we had the grand total of one fuel related issue with any of the bikes we know of. It was simply a one off case of badly stored fuel causing all sorts of bad running issues. BUT as we got further into 2013 we got more and more calls about bad running and more and more cases where it turned out to be fuel. Towards the end of 2013 these issues reach silly levels, with some customers in desperation having their bikes trailered to us so we could find the route cause of many running issues. Fitting a remote tank with newly purchased premium grade fuel fixed them, so the conclusion is the E10 fuel is now generally available and causing some real problems across a range of bikes including 2-strokes, 4-strokes, small commuters, large tourer, well everything really.

I don't want to get overly technical as there are already many sites offering lengthy technical arguments as to why E10 is good or bad.

Main problems as far as I can tell.

Ethanol has less energy than petrol, so you will either need to burn more or go slower. E10 contains 3% less energy than standard unleaded so you'll need to burn 3 % more to go as far.

Don't confuse energy with octane. Octane is the ability to resist auto ignition due to compression (knock) and actually ethanol is better than petrol in this respect. This potential benefit is of no use unless you can raise the compression ratio of the original engine.

Ethanol is hygroscopic, that is it readily absorbs water from the air. This is one of the biggest issues, once it becomes waterlogged to the point where it can not absorb more it continues to attract water that simply sits in the bottom of the tank. I've had many cases of customers complaining of water in the tank and asking were on earth it has come from. The answer is the fuel and technically it's know as phase separation.

E10 fuels degrade very quickly. It's hard to say how quickly but the estimates seem to range from a few weeks to a few months. The octane drops, it forms gums, and generally becomes much harder to ignite and produces a great deal less energy when it does. I have had cases, where I was convinced the tank was full of diesel rather than petrol, but it was in fact just E10 that had stood for a few weeks.

Ethanol may attack some rubbers, seals and plastics used in fuel systems. Ethanol molecules are smaller than petrol and can permeate nitrile rubbers causing them to swell, and soften. There is no evidence that it attacks viton. This is why I have viton cap seals made for our range of Jawa motorcycles and fit them as part of the preparation. The originals were cork and E10 appears to attack the glues holding the cork together.

Ethanol may corrode aluminium components in the the fuel system. However (and rather strangely) if the water which ethanol attracts can be kept in solution rather than dropping out (phase separation) test have shown that aluminium corrosion is not an issue.

What can be done to protect your engine from the worse effects of Ethanol.

Firstly insist at every opportunity that all fuel is clearly labelled with the ethanol content E5, E10 etc. It seems ludicrous that we are not allowed to know what we are buying and filling our tank with.

If it's not labelled assume it is E10 (for 2013/14 unless the maximum permitted is changed)

When ever possible buy your fuel from a petrol station which is busy and has a high turn over of fuel. The degradation of E10 starts from the day it is produced, not the day you buy it.

Use an additive, but be careful here, some actually contain ethanol (yes, amazing isn't it). Some are not safe with catalytic converters and will contaminate them leading to huge bills. Some will not mix with other additives for example lead substitutes. If you aren’t certain ring the manufacturer and ask, if they can't answer, buy something else.

Which fuel hose to use with Ethanol blended fuels.

Check all rubber hoses frequently and be prepared to change them for ethanol proof alternatives. Look for any signs of swelling or weeping at joints in the system. There are no additives that can protect against this, whatever they might tell you. There are many companies jumping on the band wagon selling what they claim is ethanol proof fuel hose. Here are a few I have seen for sale.

Silicone – Actually only rated as good 'B' for ethanol (not excellent) and severely effected 'D' not recommended for unleaded petrol.

PVC – Rated only as fair 'C' for ethanol and fair 'C' for unleaded petrol.

Tygon – Rated only as fair 'C' for ethanol and fair 'C' for unleaded petrol.

Viton – Which is the only flexible hose I have found rated as excellent 'A' for ethanol, unleaded petrol, leaded petrol and diesel. We therefore sell Viton fuel hose. Yes it is fairly expensive, but it is very good. 

What additives do we use at F2 Motorcycles Ltd
To protect unleaded valve seats and boost octane we use Millers VSP. It's been proved over time, and many people swear by it. Most importantly we know of no case of it causing an issue. However it must not be used with catalytic converters. It is however fairly expensive.

To protect unleaded valve seats and boost octane at a lower cost we use Castrol Valve Master Plus. Again it has been proved over time, and there are no cases of it causing problems. However it must not be used with catalytic converters.
To protect unleaded valve seats without boosting octane we use Castrol Valve Master. Again it has been proved over time, and there are no cases of it causing problems. However it must not be used with catalytic converters.

To boost octane without addition valve protection, we just buy premium unleaded and pay the extra. No issues with catalytic converters.

To protect against many of the problems with ethanol blends we use Star Tron. You've probably never hear of it but it's been protecting the marine industry in the USA for a few years now. Problems with ethanol are only just starting to surface, so most of the additives will be unheard of, or worse unproven. Star Tron is safe with catalytic converters and mixes with various octane boosters and lead substitutes.

Our experience of Star Tron additive.

As the frequency of fuel issues with E10 increased we started researching various additives. We dismissed any that contained ethanol, any that were brand new and untested and any that were not safe with catalytic converters. We wanted a single, safe, low cost additive that could be added to any petrol vehicle including EFI, carburettor, 4-stroke, 2-stroke, catalytic converter, or not.

We looked at the main issues we had experienced and concluded it was mainly fuel stability (it really doesn’t seem to last more than a few weeks) and water contamination. Early formation of gums and varnishes being particularly frustrating as they restrict small galleries in modern carburettors usually requiring a full ultrasonic clean to rectify. Early signs of fuel degradation can be as minor as slight hesitancy to start, right through to the inability to hold a stable idle even when warm. Accepting no additive can help with the fuel hose degradation we had a short list.

At the time Star Tron did not have a UK wholesaler so we contacted the factory and they kindly shipped us some samples for testing.

Please note these are not scientific tests, and we do not have a multi million pound testing facility, but we do understand engines, and we are sick and tired of problems caused by E10 fuels.

First Test.

1977 Austin Allegro 1500 with SU carburettor. No catalytic converter, no clever electronics. Half a tank of E10 fuel with correct ration of Castrol Valve master Plus, which has been in there for 3 months. This car is not used over the winter so gets to stand with old fuel in it. Attempts to start with untreated fuel proved unsuccessful, but with a battery booster connected it did eventually drag some old fuel from the tank and start. Warm up was difficult and even once up to temperature the idle was erratic. Opening/closing the throttle quickly (to clean it out) had no effect on the idle.

Mixed enough Star Tron for all the fuel in the tank with about a ½ litre of fuel and added this to the tank. |I only pre-mixed so the very small quantity of Star Tron actually made it to the tank as rather than potentially sitting in the filler neck. To be clear, the fuel I used to disperse the Star Tron, was probably worse than the fuel in the tank, as it was dark brown and had been removed from one of the bikes that arrived as a non runner.

Left it a few hours, Star Tron don't say how quickly it works, but I assumed not instantly. Also wanted to let the engine cool.

Attempted to restart, still didn't really want to start, but to be fair the treated fuel was in the tank, not the carburettor. Once it started the erratic idle was back as before, and warm up equally painful. But after a few minutes allowing the fuel to get from the tank to the carb, it was almost like a switch had been flicked. The note of the engine smoothed, the idle stabilised and all was back to how it had been several months earlier when the fuel was new.

This is a single test, but it does seem to give some credence to the manufacturers claims that it stabilises fuel and cleans gums from the fuel system.

Second Test.

Skoda Falicia 1.3 fuel injected hatchback. This is my daily drive but it only does very low miles so a tank of fuel might easily last a month. Started missing and became increasingly hard to start. Got so bad it was missing even when warm at 50 mph. Added Star Tron at the recommended amount and drove for the next couple of days to see if things improved. Nothing improved at all. Still missing and still hard to start. Opened the bonnet and noticed corrosion round one of the coil packs. Removed the coil packs, cleaned everything, put it back together and all missing disappeared. Easy to start and now runs well.
My conclusion is rather unsurprisingly that Star Tron will not fix an underlying ignition fault. Shame, but true.

Third Test.

Ural 750 carburettor engine. Last used in the summer some months ago and left with old fuel in the tank. Almost impossible to start without attaching a bigger battery and winding it over for 30 seconds. When it did start it would not run without both chokes open suggesting the idle jets were gummed up. Added correct amount of Star Tron and gave the bike a good shake to mix it well, like the old 2-stroke days. Attached jump battery and started the engine after much turning over. Once warm, turned the chokes off and it sat there with a perfect idle. Next day it started without the additional battery almost as soon as the starter turned, warmed up quickly and again had perfect idle.

So this is the second time that Star Tron appears to have stabilised fuel and cleaned the old gum out of the jets.

I have now let the bike stand unused for 2 weeks, and today it started first touch of the starter button.

Fourth Test.

250 4-stroke twin with twin carburettors. Not used for several months, but luckily the carbs have handy drain screws in the bottom. Would not start, so drained the carbs of horrid brown old fuel and let them fill up again from the tank. Still would not start, so repeated the drain and refill to try and clean them out. Left it standing for a few hours and drained then refilled once more. Still would not start. Added Star Tron at the correct ratio. Drained the carbs and allowed them to refill from the treated fuel in the tank. Started and ran badly for a minute and then ran perfectly. Star Tron really does appear to restore old fuel and take the gum out of carburettors.

How can F2 Motorcycles Ltd help with Ethanol blended fuels such as E10.

Following my research and the tests above we now stock.

Viton Fuel Pipe, the real stuff, not some Chinese pretend product. Allow enough to route with gentle bends as it does kink easily.
Link toViton Fuel Pipe at F2 Motorcycles Ltd

Star Tron fuel additive, straight from the manufacturers and we only sell the concentrated type.

Star Tron is not magic, it may not cure all fuel related problem, the company makes many claims for their product which we can neither prove or disprove. However, my tests are enough for me to use it in all my vehicles and recommend it. The cost of treating each litre of fuel is far less than buying a premium grade fuel. Premium grade may contain ethanol so buying expensive fuel may not solve the problem anyway.

A simple warning about fakes.

Viton is expensive, if you see a deal that looks to good to be true it probably is.
Star Tron comes in several concentrations, We've seen the weaker concentration being sold as the stronger type. It is very possible to put kerosese in a bottle and sell it as Star Tron if you are a dodgy faker with a label printer, We only source and import our products direct from the manufacturer, so we know it's real. 

Wednesday, 1 February 2012

L414 6 volt Dynamo fix

This only applies to the 6 volt dynamo fitted to Ural M63/M66, Dnepr MT9 and the sidevalves
At F2 Motorcycles we get emails about the L414 dynamo not working on bikes that have not been used for a while. 99% of the time there is no need to replace it.

I thought I should share my standard reply to these emails.
It goes something like this.

Monday, 2 January 2012

Winter Salt Protection - ACF50, FS365 or WD40

Winter is on the way. In the UK winter means road salt, and road salt means corrosion. There are a few products on the market that claim to help reduce corrosion. Some work very well and some are just a waste of your time and money. The best way to stop your motorcycle corroding is to wash it, dry it and place it somewhere completely dry. This makes using it a little awkward, so lets take a look at some alternatives.

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 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.

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.