Hoses from petcocks

[johnstewart]

Which hose should be connected where, coming from the petcocks? (79 XS11 special, FYI)

I had my tank off for a while trying to debug my headlight problem... when I put the tank back on I'm not 100% sure I connected the hoses to the right places. I think the rear petcock connector in each side runs directly into the 4-way connector. The front one runs into a tee (one side of which goes to that 4-way connector).

It's sort of running like it's running out of gas. When I throttle hard it seems to run okay, though. It's just when running in a high gear at relatively low speed that it's rumbling and not purring...

...so I'm wondering if I got vacuum/fuel mixed up or something. How that all works is a total mystery to me, and Clymer doesn't seem to show that detail.

The only other thing I did at the time was change plugs. I didn't gap them, but they looked good out of the box (they usually are spot on when I've checked 'em before, so I usually don't bother)... but wanted to check the fuel/vacuum lines first.

thanks!

[John]

It sounds likeyoou have them attached properly. The rearward nipple on the petcock goes directly to the octopus (4way connector) and the forward nipple is the prime side. It T's into the output fuel line down stream of the octopus, therefore bypassing it in Prime function. The vacuum port on the octopus is suipplied from #1 carb boot, where it bolts to the head. The petcock positioning is: down is on, up is reserve, to the rear is prime, and forward is off. You may want to check the fuel tank vent hole that is in the center of the fuel cap. If that is plugged, it will build up a vacuum in the tank as the fuel draws down, and will tend to hinder the fuel flow. Crack the cap open and drive it around and see if the symptoms go away.