Fuel/vac line routing

[DarinMac]

1982 GS650. I removed the gas tank to replace the camshaft cover gasket. Reassembled and now it will only run at high rpm and/or full choke. I may have put the fuel/vacuum lines on wrong but I’ve switched them back and forth and it doesn’t help. Petcock has two lines coming off-a smaller and a larger and is operating correctly. There are two Tee nipples on the rear side of the carbs -one between carbs 1 and 2 and another between 2 and 3 (from left to right in driver position). There is also a nipple on the motor side of carb 2 with nothing on there. I need to know for sure which lines go where from the petcock and what to do with that nipple on carb #2.

thanks!

[tom203]

There is also

a nipple on the motor side of carb 2 with nothing on there. I need to know for sure which lines go where from the petcock and what to do with that nipple on carb #2. zz0.1un3eb7zlpszz

edit: this site is fighting me today!

there are two vent hoses that just hang over back of carbs

[Big T]

The nipple on #2 is the vacuum line for the petcock
The other 2 are vents for the float bowls
The fuel line goes to the big T between the 2 and 3

[Rich82GS750TZ]

Yes, what Big T said. Not shown is the other vent port between 3 & 4.

[DarinMac]

Thanks. I now know they are connected properly to the petcock. Assuming I don’t need hoses on those vent nipples. I still have the same lean bog which wasn’t there before I started dinking around ☹️.

[DarinMac]

Got er done. I had to prime the daylights out of it to get it to work-like drive it a few miles around the hood. It’s great since then.

[Who Dat?]

Thanks. I now know they are connected properly to the petcock. Assuming I don’t need hoses on those vent nipples. I still have the same lean bog which wasn’t there before I started dinking around ☹️.

It will actually work better if you DO have hoses on them.

Those vents are the atmospheric reference for the float bowls. The pressure difference between the bowls and the venturis determines how much fuel flows through the jets. There is a bit of turbulence behind the engine. That will give rapidly-changing pressure 'signals' to the bowls. If you have hoses on them, you can route the hoses over the back of the airbox, or end the hoses under the seat, which is a much calmer environment.