Repairing the Triple


Disclaimer: The Speed Triple here has 50,000 miles (80.000km) on it. It had no issues whatsoever until it passed the 20,000 mile-marker.

2007 Speed Triple
If you own a Triple or you’re thinking about owning one, you may find the following hints very helpful. Triumph’s inline three-cylinder engine is legendary, and rightfully so! But anything that turns this superior engine into a motorcycle is legendary only for its many failures. The German in me keeps shaking her head at the inferior quality of most Triumph parts and while one may argue that Triumph is using cheap parts to keep the cost of the bike down, I can only point to my Japanese bike: lower cost, much higher reliability!

Copper Anti-Seize Lubricant

There are a few items you will want to buy along with a Triumph – 1) a decent digital multimeter that reads DC-Volts, AC-Volt, Ohms (Ω), and Amperes, 2) a variety set of motorcycle wires and connectors, and 3) an extra set of fuses because chances are that you’ll blow one here and there while working on the bike.

Dielectric Grease

And while you’re at the auto parts store, buy some Loctite (to eliminate the vibrational loosening of screws and other mechanical fasteners), some Copper Anti-Seize Lubricant (to prevent seizing and corrosion on your spark plugs), and some Dielectric Grease (to keep the water away from your spark plugs). Every bike is different and I can only speak for the one I have had the pleasure of repairing but after searching the web I came to realize that many Triumph owners suffer from the same problems.

Triple wiring diagram

The battery on the Triple has been acting up from the very start – but we’ll get to that later. The electrical system has had many issues, the brake light and the turn signals went on strike for no apparent reason and it took a while to find the source of the problem (which entailed cutting open most of the wiring harness): There was a short in the wires leading from the starter to the turn signals and brake light … (You may find this Triumph wiring diagram and the key to the wiring diagram very helpful.)

Torn wires - fixed with blue crimp connectors

Not long after that, the bike suddenly died in mid-ride and no longer showed any sign of life. The usual suspect -the battery- turned out to be in working order (multimeter!). Walking around the bike while mentally preparing to take the whole damn thing apart, we noticed that a bunch of wires leading from the ignition into the bike were torn. Apparently, Triumph is trying to save money (pennies … really) by keeping the wires as short as possible. With every left turn, the tight wiring harness kept rubbing against the steering head until the majority of the wires finally ripped – at the same time! Once the problem was identified, it took less than 15 minutes to fix it using crimp connectors – that way, we could add about 1/2 inch to the length of the wires which gave it just enough slack to no longer rub on the steering head during left turns (see photo).

Triple cylinder head

Another problem of the Triple was water flooding the spark plugs. If your engine turns over but has trouble starting up, water in the spark plug wells is probably the culprit. It most likely comes from riding in the rain, but it’s very common among most Triumph bikes so there may be different causes for this particular problem. There doesn’t seem to be a cure for it, but Dielectric Grease seems to keep the water from running into the wells if applied generously to the rubber sleeves.

Like most bikes, the Triumph certainly appreciates a new air filter. The OEM filter is expensive and pretty much worthless – K&N is the way to go: lower costs and a life time warranty are hard to beat!

Broken R/R and stator

Another problem that many Triumph owners run into is the battery charging system. We were replacing the battery every 10 to 12 months until one day, the bike wouldn’t start after a three mile trip to the gas station – in spite of the fully charged, brand new battery that we had just installed. A quick multimeter check showed that the battery was loosing charge while the engine was running. If you ever run into a similar problem, here’s a great fault finding flow chart, courtesy of Electro Sport Industries.

Burned Triple stator

Guided by wishful thinking, we checked every connection from the battery to the fusebox to the regulator/rectifier (R/R) to the stator, hoping for a broken wire or a bad fuse box. Eventually we had to look the truth in the eye: broken R/R and subsequently fried stator. Only a multimeter can tell you if the R/R is fried – it has no servicable parts and must be replaced if broken. As for the stator, a quick look tells you everything you need to know: if one or more coils look black and burned, it’s time for a replacement.

Yamaha Stator

We were determined not to buy the OEM stator – first of all, because it’s of low quality (you can tell by the way the coils are wound) and also because they are totally overprized. You can get double the quality for half the price. We decided to go with an aftermarket stator sold by

This re-designed and improved Yamaha stator fit the Triple perfectly, it was a walk in the park to install it. When we removed the crank case cover, half the gasket stuck  to the crank case, the other half to the cover, so we had to scrape it off. It’s actually really easy to make your own gasket, if you have the patience (check out this YouTube video) but we decided to go with a liquid gasket maker which came in a 3.5 ounce tube. Once you have everything in place, you just apply it generously on both sides and screw the cover back on the crank case. The gray paste will dry pretty quickly and seal the cover very nicely (the crank case is full of motor oil so you want to make sure that everything is sealed well).

Brand new R/R

Because the broken stator fried the regulator/rectifier (R/R), we had to replace it as well. A rectifier is a set of electronic components that turn AC into DC, which you need to charge a battery for instance. A regulator is a resistor that only allows a pre-specified amount of voltage to go to the battery. The excess voltage is sent to ground so as not to over-charge the battery. There are no serviceable parts in an R/R so when it’s broken, you’ll have to replace it. We ordered an aftermarket Triumph Speed Triple 1050 Heavy Duty MOSFET Regulator Rectifier with an impressive 50 amp capacity. This 50 amp R/R is able to handle much more current than the OEM Triumph part. It came with plug and play connections to plug right into the wiring harness. Because it’s a little smaller than the OEM part, we had to drill and extra whole in the plastic bracket underneath the seat, but other than that, the installation was as easy as it gets.

One thing we noticed while in the process of hunting down this problem in the first place is that the fuses were lightly charred and the plastic casings seemed a little melted. And sure enough, it didn’t take long after we had installed the new stator and R/R for a couple of the fuses to blow. They’re cheap so you might want to replace them along with the other parts.

If you ever run into problems with your Triumph that are not described here, check out – a very comprehensive forum on anything Triumph.


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