Honey, why does the house smell like Petrol?
Fixing Triumph fuel fittings that should have been fixed before they left the drawing board

Ready for its closeup
Miss Gill's Speed Four in the studio of a local TV station, where they usually film their cooking segments. We were there to promote Capital City Bikefest.

The Triumph Speed Four is a little-known gem of a motorcycle based on the fully-faired TT600 supersport.

But where the TT600 was released too early - it was the first digitally fuel-injected 600cc bike on the market and suffered from poor fuel mapping and consequently horrible reviews - the Speed Four came out after the issues were resolved and continued in the Triumph lineup even after the Daytona 675 came out.

Triumph made little compromise with the Speed Four. Unlike many factory streetfighters which substitute dirt-bike bars and other items, it keeps the clip-on bars and high pegs of the donor bike. While there was some mild de-tuning (a few less horses, a few more torques) Triumph truly hung a pair of lights on a TT600 chassis, fashioned some missile-launcher intake tubes to replace the ram air ducts on the fairing, and called it a day. In a 2008 Ride magazine reader's poll, the Speed Four - then out of production - still beat the Daytona 675 for handling and suspension. It was that good.

However, like many Triumphs, including the TT600, the Daytona 955, Sprint 955 and others, it suffers from a design defect that is inexcusable: it uses plastic "dry break" quick connectors to plug the fuel lines to the gas tank.

You don't have to be an engineer to predict what is going to happen to bits of plastic subjected to vibration and repeated heating and cooling over time. It's going to harden, and it's going to crack. And when it is the only thing standing between a tank full of petrol and a hot engine, you have a very dangerous situation on your hands.

Sure, Derek, those'll hold up to years of heat and vibration - the recalled fuel couplings.

Triumph acknowledged half the problem, replacing the plastic male fittings with metal ones for free as part of a recall. However, they refused to replace the plastic female fittings under the tank. Sure, if they failed while under warranty, you got more plastic fittings. If they failed out of warranty, y'er on y'er own, mate.

Part of this is undoubtedly expense-related. Replacing the hose couplings takes five minutes. Metal fittings are more expensive, and replacing the tank fittings takes more like an hour and requires draining the tank and a uttering lot of profanity, since they were installed with an epoxy-like sealant that causes them to break off. More on that in a minute.

The bottom line is that Triumph will not admit the problem. But there shouldn't have been a problem in the first place. Even the most gormless stoner sitting in the corner of a rural Kentucky high school shop class could tell you that it would be better to use metal fittings, but this was designed by engineers, who probably never took a shop class in their lives. Similar issues often crop up, which makes me believe that those who design bikes and cars have probably never held an actual wrench, although they may have seen CAD drawings of one. That is why, when I am elected Dictator for Life, no one shall be granted an engineering degree without spending at least one semester getting their hands dirty in an actual repair shop.

In the case of Miss Gill's Speed Four, the failure came to light due to the odor of gas in the garage. This is not unusual, as there are several bikes with manual fuel petcocks that have to be shut off, and sometimes someone forgets to shut them off.

However, when the house itself began to smell of gasoline, we knew it was a bigger issue. A sniff test singled out the bike, and when the tank was unbolted, gas began dribbling out of the broken fitting. There's your problem.

If you look closely, you'll see circular scratches on the plate around the fittings on the right (the one on the left is the electrical connection for the fuel pump). Apparently this is not the first time the bike has had this problem. It probably got fixed under warranty. With more plastic crap.

Step 1 is to drain the tank of fuel, which is a little difficult because it will only dribble out of the broken connection. It's easier and faster to open the filler cap and dump it. I have a plastic bin that I use just for that purpose. Keep it clean and you can reuse the gas, or put it in your lawn mower or car.

Next, you have to remove the locking hardware on the fittings by pushing down on the little plunger and removing the sliding plate. There is a spring on the side of the plate and one under the plunger - do not let them fly out.

The reason for disassembly is so you can use a deep socket to remove the fittings, rather than a wrench, reasoning that having six points of contact will more evenly distribute the torque and make the fitting less likely to break off.

The joke's on you! The fitting will break off anyway.

Seriously. Unless you are very lucky (and if the fittings do unscrew without breaking, go buy a lottery ticket immediately!), the fittings will break off flush with the base and you are now down the rabbit hole.

The next steps I describe may be somewhat controversial, as the interwebs are already full of stories by other unfortunate owners who have fixed this very same problem (even though Triumph says there's no problem). You must remove the threaded parts, but to do that, you must remove the bits of valve left inside the threaded parts, and some of those bits could potentially fall into the fuel pump assembly, which looks like this, from my TT600.

To get there, you must remove the assembly from the tank and disassemble it, which will inevitably mean ordering new parts, especially the giant o-ring that seals the whole thing when you reassemble. Unless you have spare parts lying around, figure at least an extra week. Many owners do this complete disassembly.

Or you could just start pulling bits out with pliers like I did, being careful not to drop anything down the hole. I didn't. But it's a small hole and the parts are fairly large - remember that this is actually a valve made to stop up the hole when the fuel hose is disconnected, so of course it is larger than the hole.

Once you get the valve out, you can use one of two methods to remove the remaining fitting. I used both. The first involves taking a large screwdriver and heating it with a torch - preferably away from the tank and any residual fuel or fumes - then sticking it into the plastic fitting, where it will melt two slots. Remove the screwdriver and let it cool, then insert the screwdriver into the slots and carefully turn.

The other method is the tried-and-true ez-out. The fittings requre a large one, and you'll probably have to buy it separately because most sets do not include one large enough. I already had one, because I have a TT600, which had the plastic fuel fittings, and you can guess the rest. Anyway, gently tap the tool into the fitting until it grabs sufficiently and then turn.

Once those are out, you are left with a bunch of crappy thread sealant that needs to be cleaned out.

I used a small awl to scrape the threads clean. Since the bits of gunk ARE smaller than the hole into the fuel pump assembly, I held a shop vac over the thing while I scraped so that any dust and chunks were sucked up while I cleaned, rather than falling down into the pump.

Once cleaned, it's time to insert the new fittings. These are not standard hardware-store items. The problem with the plastic connectors was so bad that Team Triumph in Wisconsin actually went to the trouble of putting together kits with metal connectors, but those are no longer available. I got mine online from Quick Couplings. The tank fittings use 1/4" British Standard Pipe Taper (BSPT). Here's more than you want to know about that. The hose fittings are different sizes, because the send and return hoses are different sizes. You can re-use the hose fittings if they have already been replaced with metal items, although you may want to put new o-rings on. Here are the part numbers for everything:

  • LC23004 - 1/4 Hose Barb Non-Valved Elbow Coupling Insert
  • LC23006 - 3/8 Hose Barb Non-Valved Elbow Coupling Insert
  • LCD10004BSPT - 1/4 BSPT Valved Coupling Body (you'll need two of these)

I used plumbing tape to help seal the threads (some interwebs say yea, some say nay, use your own judgement). You do not want to screw the new fittings all the way into the tank; you'll strip the threads. BSPT threads are designed with a taper (hence the name) that increases toward the base, sorta like a wine cork with threads. Screw it in tight enough to seal, no more. You will have to disassemble the locking mechanism if you want to use a deep socket. The arrow below shows the hole where the spring and plunger go.

Once tightened, reassemble the locking mechanism and you're finished with the tank.

If you're putting on new hose fittings, do that. Note how the top hose (3/8") is larger than the bottom (although both use the same size insert for the coupling with the tank fitting).

Before reassembly, I used some hi-viz orange duct tape to mark which hose went to the "red" fitting. Make sure you plug the right hose into the right fitting.

That's it. Reassemble. Refuel. Ride.

Return home