Sometimes problems aren’t as straightforward as they seem
You’ll remember that, in the April issue, I had written about choosing a new motorcycle. Well, I now own a brand-new 2022 Triumph Speed Twin 1200. While I love the bike, the affair stumbled at the start.
I picked it up at my local Triumph dealer, Moto Montreal Cycle, last April. However, because I couldn’t get a ride there, I loaded it into my pickup and drove home. When I got home, I took it for a brief ride and accumulated 75 kilometres.
A busy schedule kept me off the bike for another three weeks, at which point I pulled it out of the garage and fired it up. It idled fine, but when I popped it into gear and let out the clutch, the engine died. It started up again with some difficulty but would stall repeatedly as soon as the throttle was opened. It was acting as if it was being starved of fuel. Having topped up the gas tank at the end of my last ride, though, I knew it was full of gas. Eventually it wouldn’t fire anymore.
I could hear the fuel pump cycling every time the ignition switch was turned on, so I knew that worked, and the engine light was off, so the bike hadn’t picked up any trouble codes. I then pulled the sparkplug wires and checked for a spark. It was long and strong. Confident it was not a major engine failure, I nonetheless pulled the sparkplugs and performed a cursory compression check with my finger, which only confirmed that there was no internal mechanical problem.
When used properly, the diagnostic computer makes life easier for technicians. If you follow its workflow, the computer will perform various tests in logical progression, only moving onto the next test after a specific test is performed first. Skip a step and you might end up in a never-ending circle of doubt.
After performing various tests on the computer, Chris found nothing wrong. Next, he performed a fuel-pressure test, which the bike also passed without a hitch. Yet it still refused to start. Chris asked me to leave the bike behind so he could give it a closer look.
A few days later, I got a phone call telling me that my bike was running again. Elated that I would once again be riding my new Triumph, I asked Chris what he had discovered. To my dismay, he replied, “Nothing.” Apparently, while he was performing various tests, the bike fired up and was now running fine. While neither of us were happy with this outcome, we agreed that I would take the bike home and ride it.
After thinking about what the problem could have been, I deduced that it was likely that the gas had been contaminated by water when I filled the tank. The distance from the gas station to my house is one kilometre; if there was water in the fuel tank, it’s possible that the bike ran fine during the short ride home, since the water was still dispersed in the gas after filling the tank. As the bike sat unused for three weeks, the water separated from the gas and sat at the bottom of the tank. The water then worked its way into the fuel rails after I started the bike. All the cranking during testing probably pumped the water out of the tank, and clean gas was once again flowing in the fuel lines.
One Sunday morning, I took the bike and headed north toward the Laurentian Mountains. It ran flawlessly as I made my way through Montreal traffic, and ran fine as I got up to speed on the highway. However, as soon as I got on the gas to pass a car, it lost power and stumbled. Under a heavier load, it was still starving for fuel. It wasn’t water contamination after all. I scheduled another dealer appointment.
Chris finally found the problem: the fuel line leaving the tank makes a 180-degree turn toward the fuel rail, and it was kinked at the bend, thus restricting the flow of fuel. Pressure tests didn’t reveal this because the tank had to be lifted at the rear to connect the gauge to the fuel rail, and this would remove the kink in the line and give good test results. Chris remedied the issue and after several hundred trouble-free kilometres, I still love my new bike.
