Vacuum Hose missing? Im a newbie

[WanderingSlacker]

Hello everyone, I am new to motorcycles and passed the MSC course a few weeks ago and just picked up a great 2001 GZ250 with only 350 some miles on it. I got it checked out and it passed inspection and the shop didnt find any issues with it.

I find that if I ride with the fuel line on "on" or "res" the engine will die out and it can only be ridden without issue when in "prime". Long story short after searching around here for similar issues I found that I should probably check the vacuum hose to the petcock. Low and behold it was gone. I took the fuel tank and seat off and cant for the life of me find out where the tube should be or where its located. Can anyone help? I have no experience with bikes but dont mind getting my hands dirty.

Any pictures or anything that can help? I think theres supposed to be a t joint with a hose that connects to it (from what I saw on someone elses bike) but I didnt see anything like that on mine. Any help would be appreciated!

[spldart]

On the side of the carb closer to the engine there is a small tube. If you pull the tank and seat,
sit on the bike and pretend you can see through the frame it faces up and to the left.
A small vacuum line fits from there to the back of the petcock.
It's real close to the engine side carb clamp. Not the airbox side.
If a shop missed this then they weren't very thorough.
However. If your talking the typical safety inspection for your typical DOT then they wouldn't know better.

edit: and the bike runs fine with this line missing in prime? did someone plug the fitting at the carb?
Normally this hose being missing and no plug on the fitting at the carb would mess with idle.

[WanderingSlacker]

Thanks, I will take a look after I get home from work tomorrow. Honestly, Im not sure if someone plugged the carb. From what I read it should work ok because prim will allow gas to flow properly, while not having the vacuum tube will cut off gas to the engine causing it to die mid ride. Please correct me if I misunderstood though. Def dont want to cause any issues on my bike. It could explain why I had to turn the choke on full for longer than I expected, but I assumed it was just me needing to warm the bike up. Honestly, being new to riding, I dont really know the difference between warmup or it shutting down for other issues. Thank you for your response. I will try to take pictures and find the vacuum tube you described.

EDIT: What size tube is should I use? I dont know if its missing or not, but I might try and buy a replacement tomorrow just in case its been removed for some reason.

[spldart]

If unplugged you have a vacuum leak throwing off the a/f mixture to the engine.

[spldart]

I went ahead and looked it up.
Download the service manual for the gz250. Linked on this sites forums.
Open manual and go to section 4-4 (fuel and lubrication system)
Third image down reference by the '2' "Vacuum hose"
You don't have to remove the carb but that image is showing you the side of the carb
that faces the engine

'You have arrived at your destination' XD

[WanderingSlacker]

THANK YOU! I took your description from yesterday and found the hose! Seems like the guy that cleaned the carbs tucked the vacuum hose with some of the other cables :p Your description helped me find where in the carb it was so I snaked it out and plugged it in. Took it out and not a single issue!

Also, thanks for the location in the manual. I thought I searched the whole manual. Must have missed that part. Thanks again for the help spldart

[spldart]

Enjoy the bike