Triumphrat

TRIUMPH3FANMAN

I have a 1996 Triumph Trophy. The bike has an issue for a while now. It will often run fine for up to 140-150 miles before it will bog down and become vapor-locked I'm guessing and die on the side of the highway. My fix has been to open the cap, and it usually has a sound like it's releasing pressure. I usually get about 40mpg average with the bike. Don't know if that is reasonable. But I am wondering what's going on. I also had it bog down and die on a hot summer day this year(about 90 degrees) when I was riding on the interstate. It only had about 70 miles on the tank of gas this time. Would appreciate any advice on what could be wrong with the bike. I typically turn to reserve when it dies like this, but am wondering if it's another issue besides the amount of fuel. Usually it still has 2.5 gallons left in the tank when it dies. Any suggestions on how to improve the fuel mileage would be appreciated as well. Thanks!

JohnD

You might not have "vapor lock". Check that the vent tube off the bottom of the gas tank is not kinked, pinched or plugged. Any of these events will cause a vacuum in the gas tank and prevent gas from getting to the carbs.

If you have removed the tank for maintenance, it is easy to pinch the gas or vacuum lines against the spine frame of these bikes.

I had a similar problem where would run fine, then engine would die from lack of gas. It turned out that the vent tube attached to the bottom of the gas tank was just the slightest bit loose letting outside air into the tube. I pushed it fully back onto the vent nipple and used a zip tie to make sure that the vent tube was nice and tight on the gas tank's vent nipple. Problem disappeared.

A pin hole in the vent tube will also cause this problem.