The problem, one of my friends was riding his classic motorcycle on the way back home and a spark plug blew right out of the cylinder head. After I received the call I went out to pick him up with my truck. Back at my workshop I looked more closely to the cylinder head and I believe I could repair the thread.

First, there are a number of ways to repair stripped threads. In fact, it may be possible to simply chase the old threads with a tap and clean them up. Or, as I'm currently thinking, I can insert a Helicoil. There are several types of repair inserts, but I personally prefer Helicoils. It's worth trying to fix the damaged thread with a Helicoil. When a spark plug has had a chance to marry a cylinder head for 160,000 kilometers, it's not uncommon for the aluminum threads to come out of the head with the plug. I pull and inspect spark plugs every couple of years and reinstall them with a small dab of antiseize compound, but that's another story.

A proper thread repair should last as long as the life of the motorcycle. This type of repair can be used for almost any threaded fastener, by the way. And that includes cast-iron, steel and aluminum parts. WARNING: Installing a Helicoil or other threaded insert looks simple – but it's not. Any reader out there who wish to attempt it might want to practice a couple of times on scrap parts.

When your motorcycle won't start – maybe won't even crank over – it's best to keep your cool and work through the problem logically, rather than, say throw it in the pickup truck too visit the nearest motorcycle garage.

The most common kind of 'no start' occurs when the motorcycle won't even crank over. You turn the ignition key, punch the starter button and nothing happens. Chances are it's something very minor, so let's work through it.

Start by checking the most obvious things. Do you have juice? Do you notice the normal indicator lights glowing? His is your first indication you have a live battery. Watch these lights (or headlights) and see if they dim when you hit the starter button. Understand this distinction: If the lights dim, you have a weak battery. If the lights (particularly the headlight) go all the way out, you have confirmed that the starting-safety circuit is good up to the starter solenoid. It's normal for the headlights to be turned off by the starter-switching circuits to save juice for the actual start-up (aren't motorcycle designers smart?).

Let's say the battery seems to be fully charged. Is the engine-stop (or kill-) switch in the right position? Is the motorcycle in neutral gear? Are you pulling the clutch in all the way? Many newer motorcycles have a clutch interlock switch to prevent the starter from engaging unless you pull the clutch level, while others have a clutch switch that interrupts starter operation only when the sidestand is down or the motorcycle is in gear. On some motorcycles, you simply cannot start the engine if the motorcycle is in gear or the sidestand is down, regardless of clutch-lever position.

There are loads of products that' will clean your leather motorcycle suit. Most of the leathers cleaning products are as good as any in our experience. You can buy leather cleaner products in flagons of 100 to 400ml. You can use them with a damp cloth and soft nylon brush (something like a soft toothbrush) if required to remove as much as possible from the outside and seams. Then spray the cleaner on and rub it well in with a cloth. Finally wipe with a damp cloth.

Linings do get sweaty and smelly and can be hard to clean. If they're removable, you're in luck, put them on a mild wash in the washing machine. If not you can use a helmet or clothing sanitizing spray/product, which will kill some bacteria who case smells and cover any remaining unwanted odor. You can also bundle your leather motorcycle suit up and put them, in a plastic bag, in the freezer for one or two nights. The cold will kill most of the bacteria. Just let your motorcycle suit get on room temperature before flexing them.

It's slightly controversial but we've been told by one expert you can wash leather in the bath tube. Fill it with cool water, don t use detergent and bung them in. Leave them to soak for a little while, then get cleaning with that soft nylon brush again. It's not only a very effective way to get the outside looking clean it will give the lining a good rinse as well. Let them dry naturally and feed the leather with some leather care products afterward.

Yamaha Power Valve System (YPVS) was introduced in the early '80s to tame their peaky RD two-strokes. The height of a two-stroke's exhaust port is the one thing to which they are most sensitive, so Yamaha devised a valve to lower and raise the port roof depending on revs. This allowed an exhaust designed for maximum power with the valve raised, while lowering the valve gave better torque and flexibility at lower revs. It made an enormous difference to usability.

Four-strokes aren't as sensitive to a single alteration , but using a computer – basic by today's standards – a team lead by Kiyotaka Yamebe and Hideaki Ueda worked out pressure and flow in an Yamaha FZR400's exhaust. They discovered a throttle valve located at the end of the collectors could be used to tailor the pressure waves, and the theory was supported by experiments on real motorcycles. Yamaha realized they could now effectively build a full race system then use the throttle valve, by now tantalizingly called EXUP (Exhaust Ultimate Powervalve), to tidy up any resulting dips or hollows in the shape of the torque curve.

First used on the Japanese-market FZR400, Yamaha made big claims when the FZR1000R EXUP arrived in 1989: 10% more peak power than an engine without EXUP; low and mid-range torque increased by 30 to 40%; a more stable tickover; and a quieter exhaust. Tests in California showed slightly increased CO2 emissions but significantly reduced hydrocarbons.

Is BMW paranoid about the K1300S running low on oil? The oil filler cap under the seat has a dipstick, a clear tube running from the oil tank with a sight level, the dash has a warning hazard light and the LED display also has a low-level warning.

If you run the BMW K1300S out of oil you serious need to search for medical assistance. And no, I haven't; it's used two liters in 9,500 kilometers – good considering the abuse.

I booked the BMW K1300S in for a service with one of the official Bangkok BMW Motorcycle dealers and went along to watch the technician do the deed. Computers were plugged in to check for malfunctions in anything from brake systems to bulbs by the BMW technician who was wearing latex surgical gloves.

The 9,000 to 9,500 kilometers is the usual oil/filter change and fluid checks. The BMW K1300S also got a foam insert in the front brake reservoir (apparently designed to prevent brake fluid foaming after a long time, high speed ride). The service takes half a day and the flat cost including a good amount of excellent coffee and cake was 5500 THB; new brake pads bumped it a bit more...

When riding a motorcycle, we have to rely on one type of bearing or another. There are a few different styles of bearings employed in the smooth operation of any motorcycle. For instance, there are engine bearings – roller, ball, and needle – that keep the internal components spinning in harmony. Wheel bearings allow the motorcycle to roll down the road, and bearings on the front end allow the motorcycle to turn.

The setup and maintenance of any bearing can extend or shorten its life, but especially so when it comes to the steering stem bearings of your motorcycle's front forks. For the sake of this article, we'll limit our focus to the tapered roller bearing most commonly used on big bikes.

The front fork stem requires two bearings, one on the lower triple tree and one under the top triple tree. The fork stem bearing races are pressed into the frame, and the bearings fit on the fork stem, allowing the front end to be turned from side to side smoothly. The fork stem bearings operate under a small amount of preload, which is determined on each individual motorcycle by what is known as a fall away test.

When we first viewed these KTM Eduro modded rims, they appeared to be one-off special featuring their logo bill-boarding all the way around the outside of a black KTM rim. The reality is that they are stickers, and they not only protect the outside of your easily dinged rim, but they hide blemishes quite well.

You can install them with or without the tire mounted. Make sure the rim is clean and dry. Use contact cleaner to make sure the rim surface is spotless, and make sure you do not have any chain lubrication on the rim. It is easiest to install the rim stickers when the rim is warm.

If you look closely a the master link keeper of your motorcycle chain, you'll see that one side has sharp edges and the other side is rounded, just like a flat washer. When the die stamps out the part, the process creates that rounded edge on impact. We always assumed that the rounded side should face up when you install the keeper. Not so.

That slight rounding side on the master link keeper makes it easier for the keep to come out of the slot that is supposed to hold it in place. Also make absolutely certain that the top plate is pushed down as far as it will go to expose the slot, and be careful that no dirt or dust comes between the link keeper and the master link. Otherwise, the master chain link keeper will never be really securely mounted.

While we're talking about master links of your motorcycle chain, remember that the keeper is not a reusable part. The master link keeper is made of spring steel and is usually distorted by the removal process. It can also be damaged by sloppy installation. Never lift on side of the keeper over the pin. Instead, push it on evenly.

We all have kids, and we all like to keep them happy. A Kawasaki KLX110 mini dirt bike will do fine, but a modified KLX110, turned into a 138cc little dirt devil does miracles.

A indicated we started out with a stock Kawasaki KLX110, went online and called some local Thai suppliers. The stock 110cc engine is just a memory thanks to a Takegawa Superhead with two big valves and a 138cc Takegawa cylinder. Te feed the non-stroked engine, the stock carburetor was ditched for a 26mm Mikuni with a Two Brothers Racing air filter and bracket kit. Handling the extra power is a Takegawa six-disc clutch with a manual cable clutch and cover in place of the stock parts. In the transmission, a Takegawa four-speed shift drum made the use of fourth gear possible, and a BBR heavy-duty output shaft reduced the possibilities of failure. A Two Brother Racing exhaust system rounded out the engine modifications.

The stock frame on the Kawasaki KLX110 hold up to a lot of abuse, and for this project little dirt devil, the frame was about the only thing we didn't touch. Marzocchi forks handled the suspension duties up front, and a Race Tech shock took care of the back half of the KLX110. The trick Two Brothers Racing swingarm was longer and stronger than stock – and also looked way better. Kawasaki KX85 wheels with dics brakes. Drum brakes, a fast motorcycle and a fast rider never mix well. Sik Tendencies brake adaptors made the use of the KX65 calipers possible, and a Two Brothers Racing brake pedal fit nicely with the Two Brother Racing footpeg bar.

Overcome with sunshine and blue-sky induced enthusiasm, albeit a little later than I would have hoped, I've started my crusade of motorcycle rejuvenation. I pledge to all the little jobs I've previously ignored, overlooked and bodged in my three years of Suzuki GSX-R1000 ownership. Yes, I realize most do this maintenance stuff during the raining season, but until recently the motorcycle was my only form of transport.

There is a problem, though. I'm no mechanic. I can do basic work, but I don't have the knowledge to attempt bigger jobs. I don't want to find myself halfway into a double-shark sprocket job only to hear a 'ping' which turns out to be the critical retaining pin making a bid for freedom. So, when I was offered the chance to spend a day at big bike garage learning from the people who know what they doing. I jumped at the chance. I won't bore you with my voyage of discovery and stupid questions.

We addressed the following problems on my motorcycle;