Oh, man! Do I have a story for you. Grab some coffee, or your beverage of choice...
Just over a year ago, I bought a 2013 Hyperstrada, completely stock, with ~6,000 miles for road trip duty. This after an 8-year bike hiatus, and coming from a little Ninja 250. Three weeks later, I packed my things, filled up the tank and started a 3,000 mile road trip into Mexico with my father-in-law, but first I needed to make a 400 mile trip to meet him.
First stop, Globe, AZ and I fill up the tank again; everything's going well and I'm right on schedule.
Second stop, Safford, AZ, I fill up the tank again, start the bike and it starts normally, then dies immediately. I try a couple more times, with the same result. After the third one, the bike cranks but doesn't even start. I push the bike out of the way of the gas pumps, remove the seat and start looking for a problem.
After a few minutes trying, I call my buddy back in town, who helped me decide on the Hyperstrada. He owns a Multistrada and has flipped several bikes by fixing them himself. I explain the symptom and since it's gotten to the point that it just barely cranks, we start with the battery. I go across the street to a mechanic's shop and ask to borrow their multimeter; go back to the bike, sans my driver's license, and confirm that the battery is actually not the problem.
By then, my friend has called another friend who's built bikes to run on Bonneville. In the meantime, after returning the multimeter, I try again and the bike starts up, then dies immediately after, just like before. As it gets harder to start the bike, I have to do so by turning the throttle more and more.
My friend calls back and asks if, once started, I can keep the bike revved up so that it doesn't die. I try it once and I manage to keep it running for a few seconds, so I decide to give it a shot.
5 hours have passed since the problem started; I pack everything up again, replace the seat and put my gear on, then give it another try by starting it at almost full throttle. I manage to keep the bike running at about 7-8k RPM, with a few surprised looks from onlookers because the bike is very loud. Pull the clutch lever, 1st gear and I managed to storm out of there.
Once on the highway, everything is running normally, but I dare not stop until Lordsburg, NM when I need more gas. I nervously fill up the tank and get my phone out to let everyone know that I'm finally gone from Safford. I have calls and text messages from both of my bike friends and also from family waiting for my arrival.
Everything seems normal; bike start right up after filling up the tank, so I conclude that it was a fluke. Go inside to use the restroom and when I come back out I have to finish a call mid-way because I notice a fluid below the bike. I check and it's gasoline, coming from the canister. I go to start the bike and it hesitates but starts without much problem so I continue on my way.
I finally make it by night, but I decide to fill it up again before putting it to bed. We then start our trek to the blessing of the helmets in Mexico and all but forget about the starting issue, except for when we stop and continue theorizing about the root of the problem.
The leading theory is that I overfilled the gas tank, fluid made it into the canister and caused the starting problem. Since it was only my second or third time filling up this bike, I take that as valid because at that point I had no real reference. Thus, we conclude that I wasn't careful and caused the problem.
On the way back, just over a week after the problem, I stop to put gas in that same gas station that, worth noting at this point, had been my preferred gas station in Safford in the many trips done on cars; surprisingly, the bike has trouble starting again after filling it up. Since I now know what to do, it doesn't take me long before I'm out of there.
I fill up the tank two more times before finishing the trip back home, with absolutely no problems, and by then I've started noting the level of the gasoline in the tank when filling up, which starts making our theory above weaker and weaker.
I ride through that road almost any time I start a road trip. In the next trip, I stop at the same gas station and have the same problem, so I decide to stop filling up there. On the way back, I choose a different gas station, with the same result.
I have ridden through Safford 4 times since that first trip and every single time, with just one exception, I've had the same problem starting the bike, regardless of gas station. To make it even more confusing, it is in Safford where that has only ever happened to me, so now the theory is leaning more towards the altitude of the town, because fuel level in the tank is definitely not the cause of my problem (I've mistakenly overfilled it in other towns with no problem at all; I've filled it up in a multitude of mexican gas stations, also with no problem).
A couple of months ago I decided to remove the charcoal canister from the bike. In just two days, I'm heading out that way again and I'm purposely stopping to fill up at that original gas station, let it sit for a while, see if there's any fuel dripping that would have gone to the canister, and see if it's difficult to start after.
The base for the original theory is that even the owner's manual says that if the fuel tank is overfilled, fuel might go into the canister and the bike might be difficult to start.
I'm actually looking forward to this next trip to give it a try.
