Petcock issues continued

[FJdude]

So after taking apart the petcock, checking the vacuum and gas lines they all seem to hold suction and the fuel vacuum works.

I took it out for a test ride with the petcock set to "ON" and the bike died after ~2 miles. Put the petcock on "PRIME" ran it for a few seconds then switched it back to "ON" and it fired right up like there was never a problem. Then the following day went for another ride and it died after about 10 miles, so I pulled over switched petcock to "PRIME" and back to "ON" and she fired right up and continued on for another 20 miles. And so this brings me to the present.

My hypothesis is that something in the petcock is preventing the suction from happening and the bike starves itself of fuel. But why is it so random? Why does it not happen every time after a mile or two?

It seems I have found a slippery pickle...

[Pat Conlon]

Sounds like a kinked fuel line. Check your fuel line routing.
As the soft rubber line gets warm, it will slowly pinch off the fuel flow if the line is not routed correctly.
Very common on the '84-'87 gravity fed 1100's and 1200's. (as opposed to the '89+ fuel pump FJ's)

[flips]

Hi there

This happened on my 86.The fuel lines kinked.I followed Mr blackstock's lead to fix it.

http://www.fjowners.com/index.php?topic=4411.msg38941#msg38941

Might even be a fuel cap venting issue....might need a "flapectomy"

http://www.fjowners.com/index.php?topic=2024.0

Cheers 

Jeff P

[moparman70]

yes, if it stalls again .. open the fuel cap and see if she starts and runs normally.  If so it is a fuel venting issue.

[FJdude]

Thanks guys! Your great I'll give it a try next time she sputters to a slow death 

As for the kinked fuel line, I don't quite see how switching the petcock to "PRIME" would fix the problem if the lines are kinked. I just don't see how a kinked line will starve the engine when set to "ON" and not starve the engine when set to "PRIME". It's some food for thought.

I'll check all the lines and make sure none of them are kinked under there though. Thanks again!

[Pat Conlon]

You can pull your tank off, look at the lines and everything looks fine.
Only to put your tank back on, and have the kink reappear when things get warm.

My advice is to....Follow exactly, the factory oem fuel line routing
The single hose from the petcock to the Y splitter should be run *under* the 2 branch lines.
If you run the petcock line on top of, or over, the branch lines, you will get a kink.

[FJdude]

You can pull your tank off, look at the lines and everything looks fine.
Only to put your tank back on, and have the kink reappear when things get warm.

My advice is to....Follow exactly, the factory oem fuel line routing
The single hose from the petcock to the Y splitter should be run *under* the 2 branch lines.
If you run the petcock line on top of, or over, the branch lines, you will get a kink.

I'll double check next time I have the tank off, but I'm pretty sure I have the correct routing on the fuel lines...