Any clues as to why this would happen?

Riding home for lunch I started to run out of gas so I switched over to reserve, the bike then proceeded to run out of gas and quit. Luckily a gas station was only about a block away. Got it there to fill it up and it still had gas in it ( only like half a gallon which is reserve ). Tried switching it again and nothing.

Now I just did the carb kit two weeks ago so I had the tank off and everything. There are only the two supply lines, one for "fuel on" and one for "reserve". Then it has two big vent lines that run down and out the frame.

I checked the supply lines and don't see any kinks, and the vent lines look fine.

Could a plugged vent line be the culprit? I don't think my valve is bad. I am going to pull the tank again to see if I missed something. Any of you run into this?

 

Plugged or pinched vent line would allow a partial vacuum to develop in the gas tank and that would stop the fuel flow only few miles into the ride. And opening the gas cap "fixes" the issue again for another few miles.

It's still most likely you either have a pinched or kinked fuel line between the tank and the petcock, or you crossed the two fuel lines.
In the latter case the "Fuel On" position actually uses the Reserve spigot and drains the tank pretty much all the way empty.

--
Mikko

 

It has got to be a pinched vacuum line.

When I removed the tank, I didn't disconnect the fuel lines above the petcock, just the one below so they aren't switched. And they are only about 3 inches long above the petcock so I can't imagine they are kinked.

 

Maybe you have some junk around your reserve pickup tube. +1 on the plugged vent line, made that mistake when I deleted the smog junk, but I was not even able to make it to the top of my driveway.

 

I know I am stateing the obvious but the long tab on the petcock is not the indicator. Indicator is the short tab. So long tab up is reserve. To me intuitively it would be the other way around.
I only suggest this may be your issue becuase when i got the bike I had it backwards and was getting lucky hitting the fill up everytime until I did run out and had to push to a station a block away. Pinched vent would explain runnign out first time then if it was switched to reserve & level was below the regular pickup you could not start.

 

Okay, I figured it out.

When you pull the tank, the factory air pump has a hose that runs through the two gas tank supply lines over to the air box. After installing my carb kit, I re-routed this smog line to the side of the lines. This caused just enough shifting of the reserve supply line to slightly kink it right at the nipple on the bottom of the tank. A little re-routing of lines and it works like a champ.

Yes, I thought I was nuts and checked the petcock about 20 times to make sure I wasn't loosing my mind. At least reserve didn't work right next to gas station. It could have been bad up in the mountains.

Anyways, after modding your bike, make sure EVERYTHING works before going out for a long ride.

Thanks for your help guys

 

You're welcome.

 

Once I added a fuel filter to my KLX, I didn't like the way the line was routed so I bought some extra fuel line and made it longer. For some reason after that I would only get about half the normal range. Couldn't see what was wrong so I put it back to stock and it was fine

Just one of those things

 

Selling your KLX, eh Mav? Is the KDX doing it all for you these days or is another bike waiting in the wings?

 

No so on my bike, if you look closely there is a small arrow on the edge of the tab that indicates the long side of the tab is the working side. Maybe they changed it on the SF?