Petcock Vacuum Line

[Cascadia]

Just picked up a 2009 GZ250 under 3000 miles. It was ridden only 500 miles by the last owner, who registered in 2016. So, it was sitting for a while, but the dude I bought it from works at a shop and went through it, cleaned the carb, etc. But, he said it runs best when the petcock is in prime ("PRI"), not "ON." Indeed, it stalls out after a bit when riding in the ON position but has no problems in when riding in the PRI position.

I looked through these forums and found that others have dealt with this issue (http://www.gz250bike.com/forum/showt...ck+vacuum+line) . . .

Checked the the petcock assembly and, lo and behold, it looks like the vacuum line from the back of the petcock to the carb is missing. I've looked through the parts manual but the petcock diagram does not show the vacuum line (https://app.box.com/s/bg53kxt9vwecnr0xm7ab pg. 35). I've also looked through the owner's manual and service manual.

I'm hoping someone would be kind enough to post a picture of their petcock with the vacuum line running from the nipple on the back of the petcock to the carburetor?? I understand from researching that the vacuum line should connect to the carburetor on the top-right-front.

Also sounds like some people just let the bike run in PRI and don't worry about it, but that it could cause problems with the needle.

Any suggestions? Thanks everyone!