Frequently Asked Questions

Yes. Even if you have the broken part, we usually don’t weld it back on because experience has taught us that building up a skirt from new metal is a better solution.

Probably! We pride ourselves on the quality of our welding and machining of damaged bores, and if you have seen our literature before you will probably already know what we are capable of. Sometimes (rarely) we come across situations where we do not feel confident that any repair would offer satisfactory performance or durability, and we will tell you that before we get too involved an a salvage attempt and let you decide how you would like us to proceed.

Of course, extreme damage like this will need to be priced according to the amount of work involved, so please contact us before you throw the cylinder away…

Almost certainly it will cost less to refinish all 4 bores than it would to mask the “good” ones and just fix the bad one. Of course, you should be asking yourself if the good ones are really still within specs for optimum performance, or if the whole block needs to be reconditioned anyway.

Probably yes, we were the first to introduce nickel/silicon carbide plating onto cast iron many years ago. We can probably help solve your problem – just contact us for more information.

Most orders are completed within 10 working days and sometimes much less. We always try to provide the fastest possible turnround, but schedules can change depending on workload and other factors.

View our current turnaround time

We always try to keep our prices very competitive, and we are sure you will be pleasantly surprised at how affordable our repairs are. Please contact us for current pricing.

Yes, we can repair the damage before we replate the cylinder. However, the damage was the symptom and not the cause, and unless you find the cause and fix that, you will continue to experience detonation and will damage your cylinder again.
There are lots of resources online describing the causes of detonation, and you would be wise to learn as much as you can about the causes and remedies. If you don’t feel confident in your own knowledge, talk to your engine builder.

We always try to find the best service at the most economical price depending on the destination address.
If you have a specific courier that you would like us to use, or if you want to arrange your own collection, please call us to discuss that option.

Most orders are completed within 10 working days and sometimes much less. We always try to provide the fastest possible turnround, but schedules can change depending on workload and other factors.

View our current turnaround time

We get deliveries from most carriers each day. They all know where we are so just use the one that you feel most comfortable with.
Remember when you are packing your cylinder to use a box that is plenty big enough for the whole consignment, and be sure to separate all the parts using newspaper, cardboard, rags, or something similar.

If you are including a piston, don’t be tempted to put it into the bore thinking it’ll be safe, because the bore is probably damaged anyway!

If you are sending more than one cylinder, it’s best to put each one in a box alone as described above, then put each of those boxes into a bigger box taking care to put plenty of packing material in as well so that the cylinders can’t bang against each other in transit.

If you really must use polystyrene “chips” or “peanuts”, put each cylinder and each piston in a plastic bag or a small box first. We understand that the carriers try not to damage the packages they handle but it does happen sometimes, usually due to insufficient packaging being used.

If you live locally, feel free to bring your cylinders in person…

When we process cylinders, we usually need to immerse the whole thing in some strong chemicals that will attack materials like steel, brass and so on. Because of that, we like to have all of those materials removed before we start work. Sometimes, parts are cast into place during the manufacturing process and they are impossible to remove. In that case, we will paint a protective lacquer on those parts to try to prevent any chemical attack. YOU MUST UNDERSTAND that while we take all reasonable steps to avoid damaging parts when we process cylinders, we will not accept any responsibility for any damage that does occur. If any parts are not removed before the cylinders are sent to us, we may have to make a charge for removal.

All that we really need is the cylinder itself, but it is good if we have the piston too so that we can be sure to give you the correct clearance. We can supply pistons and gasket sets at competitive prices from world leading manufacturers such as Wiseco, Wossner, Vertex & ProX if you would like us to. Remember also to include a note of your name, address, daytime phone number and any special requirements.

We accept MasterCard and Visa (credit or debit) cards. Alternatively, customers can settle their bills by direct deposit into our bank account. Please contact us for the details. There’s no need to include payment with your order – we’ll call you for payment as soon as we have your order ready to ship out. We do not accept cash or cheques.

We always try to keep our prices very competitive, and we are sure you will be pleasantly surprised at how affordable our repairs are. Please contact us for current pricing.

We have a simple form that must be completed in order for us to consider an application to become one of our dealers.
Become a dealer

Yes! Now that the bore is bigger than before, the power valve (if there is one) needs to be modified so that no part of it extends into the bore under any throttle conditions or whether the engine is either at room temperature or operating temperature. This is ALWAYS the responsibility of the engine builder. We will not accept any liability if this work has not been done properly.
Next, the cylinder head may need to be machined to suit the new bore diameter and piston shape. If this is not done correctly, there could be a reduction in performance or, in some circumstances, major engine damage may result.

Also, with a bigger bore you will now be burning extra fuel AND extra air, so it may be necessary to adjust the fuel/air mixture to suit the bigger capacity engine. Of course, that extra fuel and air needs to go out of the exhaust system after it has been burned in the engine, so that might need modification too.

Another thing that is sometimes necessary is to alter the ignition timing to suit the bigger engine. As always, incorrect mixture and/or incorrect ignition timing can lead to severe detonation.

With all of the above, and with any aspect of increasing engine capacity or performance, it is something that demands the skill, knowledge and expertise of a professional engine builder to be confident that the conversion will work as intended.

You should normally follow the engine manufacturers instructions for assembling your engine, but here are some general points of good practice:
First, you should already have cleaned your entire engine before disassembly to prevent dirt and debris from entering the engine case.

Be sure all surfaces are clean and free from previous gasket material.

If your cylinder uses a power valve assembly:

Wash the cylinder carefully with detergent and hot water (not solvent), ensuring that all surfaces are clean and free of any loose material. Wipe the cylinder wall with the lubricating oil you presently use.

Power valve parts must be free from dirt, dust and carbon. When fitted into the cylinder they must operate freely. If they do not, remove the power valve part, identify the cause and if necessary relieve the obstruction with fine waterproof abrasive paper. Never force any part.

Ensure that the crankcase internal parts are perfectly clean since any debris, which has entered on disassembly, will probably be sucked into the cylinder and cause rapid wear to your new coating and piston.

Ensure that the piston to bore clearance and piston ring end gap is in accordance with manufacturer’s specifications. Allow ample ring end gap. There is far more danger of ring butting than an appreciable compression loss. Rings typically have a minimum of 0,3mm (0.012”) end gap in the cylinder bore unless the engine manufacturer or piston manufacturer has a different specification. Care should also be taken to ensure that the end gap can be closed properly around the locating pin if applicable. It should be noted that most manufacturer’s now offer pistons of varying sizes often graded “A”, “B” and “C” etc. please call us before assembly if in doubt.

Starting your engine

Follow the manufacturer’s instructions. If these are not available the following process should be used:

• Use the same 2-stroke oil mix as you normally use (if applicable). Do not use an extra rich oil mixture during running in.
• Allow 30 to 45 minutes for running in of the new piston, rings and plated bore.
• Allow the engine to cool down. Re-torque the cylinder head to factory specifications.

Race warm-up

• Air cooled engines normally require only a short warm up time prior to racing as long as the correct running in procedure has been followed.

• Liquid cooled engines should be brought to normal operating temperature prior to racing to avoid cold seizures. These result from the piston expanding faster than the liquid cooled cylinder bore.

This is a common question we receive, and the best answer is that it is formed in the cylinder during the casting process.
Unfortunately, there are a lot of misconceptions about porosity. Some customers are worried that that a ring will catch on it or that it will cause poor ring seal. This is typically not the case. Kept in proper ranges rings will not be negatively affected by porosity. The holes fill up with oil creating a better ring seal and lowering the coefficient of friction. Some bore coating techniques actually rely on deliberately introducing holes in the surface of the bore to achieve this.

To understand porosity you have to understand what it is. Simply it is trapped gas bubbles from when the aluminium was poured. Most foundries have technologies that reduce this porosity but as a rule the deeper you go in a casting the more porosity you will find. That is why cylinders that are bored oversize are more susceptible to porosity than stock replates.

Welding can also introduce porosity. As a rule, everything is done to eliminate it but, depending on the material or its age, it may not be possible.

Another question is why does it have porosity on it now when it did not before? There are two reasons for this. Our plating process chemically removes material to allow the plating process to work. That etching sometimes exposes new porosity just under the machined surface of the bore. Our plating fills in most of the porosity but some of the bigger pits may be leftover.

The most important factor about porosity is that generally it is nothing to worry about. Every OEM has a specification on allowable porosity and we won’t normally send a cylinder out that would not pass their typical specification. After all, the piston and ring/s in a two-stroke engine are perfectly happy to pass the ports hundreds of times every second, so why would there be a problem with holes in the surface that are far smaller?

In very rare cases where it might be necessary to ship a cylinder that is perhaps marginal we would call our customer before shipping to discuss the issues.

Probably! We pride ourselves on the quality of our welding and machining of damaged bores, and if you have seen our literature before you will probably already know what we are capable of. Sometimes (rarely) we come across situations where we do not feel confident that any repair would offer satisfactory performance or durability, and we will tell you that before we get too involved an a salvage attempt and let you decide how you would like us to proceed.

Of course, extreme damage like this will need to be priced according to the amount of work involved, so please contact us before you throw the cylinder away…

Usually about 0.10mm (0.004″). We can plate much thicker than that (and often do), but as the coating thickness increases, so does the edge buildup on the ports and lead-in chamfers etc. There are also technical reasons to avoid excessive thicknesses, but there are sometimes economic reasons to plate cylinders regardless of thickness, for example if the cylinder can’t be replaced or if no pistons are available in the size that you need. Please contact us to talk about this if it is applicable.

Probably yes, we were the first to introduce nickel/silicon carbide plating onto cast iron many years ago. We can probably help solve your problem – just contact us for more information.

Because sleeves are just old news!
Why would you want to add extra weight to your machine, increase bore wear and lose engine performance?

The real problem with that kind of cylinder is the honing after plating. In a traditional cylinder, the honing tools can travel through both the top and the bottom of the bore with no obstruction. We call that a “through bore”.
But let’s consider a cylinder with an integrated crankcase.

In that kind of cylinder, the honing tools can’t travel through the whole length of the bore because the crankshaft journals are in the way. That is called a “blind bore”.

Honing a blind bore with a relatively soft surface like cast iron is fairly straightforward because our diamond honing tools are much harder than the surface that is being cut.

The difficulty comes when we try to hone our very hard nickel/silicon carbide metal/ceramic composite coating, since the silicon carbide particles are almost as hard as the diamonds themselves, and are far harder than the matrix that binds the diamonds together in out honing tools.

The effect is that the parts of the diamond tools that are constantly in contact with the bore surface (because they can’t pass through into open air) start to wear slightly compared to the rest of the tools, and so the diameter of one end of the tool becomes smaller than at the other end.

When that starts to happen, and it will, there is nothing that can be done to avoid creating a tapered bore which is smaller near the crankcase than at the end of the bore where the head attaches.

Honing just one bore may not wear the diamond tools more than just a few microns, but subsequent bores will exaggerate the taper.

The same principle applies to cylinders with an integrated head.

Honing equipment manufacturers have developed a variety of ways to combat this problem, and engine manufacturers who are making the same size of blind bore on a mass production basis can design tools or procedures to practically overcome the issue altogether.

Our business is a little different though, since we deal with an enormous range of bore lengths, diameters and configurations every day.

Since 1984, we have taken pride in making bores extremely straight and extremely round, and we aren’t willing to supply bores that we know aren’t the very best that they can be, so, until we and our tool suppliers can develop a good, reliable solution to the problem, we will choose not to process “blind bores” at our UK facility, except for engine manufacturers where the costs of special machines and tools can be justified.