Not to pick nits....but.....boiling is a temperature and pressure issue. If the tank is holding some pressure the fuel will not likely be "boiling" per se. When you opened the cap the pressure inside the tank was released and the fuel started boiling as the vapor that was flashing off at the lower pressure escaped. Similar to water boiling at room temperature in a vacuum.... Boiling means that the vapor pressure of the liquid is higher than the pressure above the liquid. When the tank was capped and (lightly) pressurized the fuel wasn't boiling but began boiling when the pressure dropped. The temperature didn't change suddenly when you opened the tank so there must be more to it than just the temperature.
Boiling Fuel Syndrome
- Thread starter awryders
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Not to pick nits....but.....boiling is a temperature and pressure issue. If the tank is holding some pressure the fuel will not likely be "boiling" per se. When you opened the cap the pressure inside the tank was released and the fuel started boiling as the vapor that was flashing off at the lower pressure escaped. Similar to water boiling at room temperature in a vacuum.... Boiling means that the vapor pressure of the liquid is higher than the pressure above the liquid. When the tank was capped and (lightly) pressurized the fuel wasn't boiling but began boiling when the pressure dropped. The temperature didn't change suddenly when you opened the tank so there must be more to it than just the temperature.
ndivita
Well-known member
I am the KC to California 2005 FJR owner to whom the boiling gasoline episode happened. Here is the deal. I do not remember whether the gas tank was half full or below half full, but I do not believe it was above half full. It was hot. I had been running the bike hard, for an extended period of time coming up Interstate 80 toward Sidney, NE. That means between 90 to 105 mph for about 20 mins. I was running between two and three bars on the heat gauge. I pulled into the gas station to refuel. I opened the gas tank, and to my shock and amazement, gasoline spewed out of the tank probably 18 inches high. It was mostly vapor, but there was definitely fuel geysering up. It did not occur to me at that time that gasoline could or would boil. I assumed that the release of pressure in the form of the vapor would have alleviated any problem immediately. I then attempted to put gasoline into the tank. This time, it spewed out of the tank even higher. At that time, I decided I had better refuel later, after things had cooled down, literally and figuratively. It scared me.
Approximately an hour and a half later, all was well, and I filled the tank up with no problem. The gentleman who first placed this post on August 4 was kind enough to talk to me about the problem at some length and offer some words of advice. Bless his heart.
I was headed to California, so there was little I could do but proceed ahead duly warned. I can tell you the problem never happened again. I can tell you that I ran the bike even harder, longer and in hotter conditions, with nary a hint of this occurring again. The bike ran like a stallion the entire way to Northern California, through the Great Salt Lake Desert in heat exceeding 100°. No sweat, no spewing gasoline, no vapor. Again, on the way back to Kansas City, I ran through that notorious stretch of US Route 50 in southern Nevada, where it was hot, and to put it mildly, I was running the bike hard, for a long time. No problems.
During the trip, I must say my confidence was shaken in the bike by this episode. However, as the trip wore on, I regained the confidence. I write this off as a fluke, due to something in the gasoline, a clogged relief valve, you tell me. All I know is that under conditions that would have necessarily produced the same phenomenon, it did not occur. In all other respects, the bike performed magnificently. This was the only glitch. In fact, the bike even seemed to run a little bit cooler after this occurred.
I have no technical background, and I am not a motorcycle mechanic. However, it seems logical to me that the considerable heat this bike emits could well raise the temperature of a less than half full tank of gasoline to the point where it could cause problems of this sort. If a valve designed to relieve pressure is malfunctioning for some reason, in addition, I could see this happening. Before this trip, I guess it did not occur to me that gasoline could boil without something worse happening. You do have to wonder about the design of a motorcycle that will allow fuel to boil under any conditions. After all, this is a high-performance, sport touring motorcycle in which it is highly foreseeable that users will run the hell out of the thing.
Every machine has its upsides and downsides. The FJR is not perfect, but it is damned close. I just wish the problem that makes it less than perfect, in my little corner of the world, did not relate to the potential for boiling gasoline spewing out of the fuel tank.
Approximately an hour and a half later, all was well, and I filled the tank up with no problem. The gentleman who first placed this post on August 4 was kind enough to talk to me about the problem at some length and offer some words of advice. Bless his heart.
I was headed to California, so there was little I could do but proceed ahead duly warned. I can tell you the problem never happened again. I can tell you that I ran the bike even harder, longer and in hotter conditions, with nary a hint of this occurring again. The bike ran like a stallion the entire way to Northern California, through the Great Salt Lake Desert in heat exceeding 100°. No sweat, no spewing gasoline, no vapor. Again, on the way back to Kansas City, I ran through that notorious stretch of US Route 50 in southern Nevada, where it was hot, and to put it mildly, I was running the bike hard, for a long time. No problems.
During the trip, I must say my confidence was shaken in the bike by this episode. However, as the trip wore on, I regained the confidence. I write this off as a fluke, due to something in the gasoline, a clogged relief valve, you tell me. All I know is that under conditions that would have necessarily produced the same phenomenon, it did not occur. In all other respects, the bike performed magnificently. This was the only glitch. In fact, the bike even seemed to run a little bit cooler after this occurred.
I have no technical background, and I am not a motorcycle mechanic. However, it seems logical to me that the considerable heat this bike emits could well raise the temperature of a less than half full tank of gasoline to the point where it could cause problems of this sort. If a valve designed to relieve pressure is malfunctioning for some reason, in addition, I could see this happening. Before this trip, I guess it did not occur to me that gasoline could boil without something worse happening. You do have to wonder about the design of a motorcycle that will allow fuel to boil under any conditions. After all, this is a high-performance, sport touring motorcycle in which it is highly foreseeable that users will run the hell out of the thing.
Every machine has its upsides and downsides. The FJR is not perfect, but it is damned close. I just wish the problem that makes it less than perfect, in my little corner of the world, did not relate to the potential for boiling gasoline spewing out of the fuel tank.
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