No petcock

[mjn12]

So I'm out riding today (first day out on the suzuki) and I find a parking lot to start practicing starting on  hills (I'm totally new) and the bike starts sputtering and dies.  I look for the petcock to switch to reserve and its not there. I thought I was going crazy. I rolled the bike off the hill and took it home, got a flashlight and found out that the previous owner had replaced the petcock with a piece of T-Shaped metal tubing.  Also, I noticed a portion of the wiriing harness - the part that runs up the right side of the tank tucked under the frame - was laying against one of the fins on the cylinder head.  Any advice on securing that to the frame? I'm thinking I might have to take the tank off to get to it since its tucked under there. Oh and does anyone have an extra petcock laying around -- I supposed I need to buy one.

[scratch]

Zip-tie the wires.  That's your first priority.

[mjn12]

yeah, before I go down the street to get gas I'm getting that taken care of. I already checked the wirres and it seems like the insulation is still good.  I'm jut hoping I can attach them somewhat discreetly and without taking the tank off.

I was under the impression that the bike needed that valve to function since the vacuum hose from the carbs attatched there as well as it regulating gas flow between reserve and primary -- then again I'm still a little fuzzy on the fuction of the vac hose.

[Jenya]

Bike doesn't really need petcock. It will function just fine without one. The only drawback is that you don't have Reserve.
Vacuume hose is how the petcock opens up the vavle for the fuel to flow. I assume that whoever removed the petcock, pluged up the vacuum port on the carb.
Otherwise, the bike would run poorly.

[mjn12]

I think I did see it capped when I was looking at it earlier.

if the fuel isn't being regulated by the vacuum pressure then don't you risk flooding more often or anything since theres always flow?

[Jenya]

The purpose of the petcock is not to regulate, but simply open or close the flow.
Carburators regulate.

The only way petcocks can regulate  (when they are broken) is to restrict the flow and cause fuel starvation. That is why the previous owner got rid of it alltogether to cure the notorious fuel starvation problem.

Forgot to mention. Another disadvantage of not having the petcock is the danger of draining the fuel tank on the ground if the float needle inside of the carburator gets stuck for some reason. That is why the stock petcock automaticaly shuts off the flow when the engine shuts off to prevent acidental fuel spilleage.

Jenya

[mjn12]

Thanks for the info.

Now I just have to think about rejetting to see if that stops it from randomly idling around 3~4k.  Sounds easy enough with a little more research and maybe a clymer manual.  Then again maybe some new gas would help me, I think the PO had that stuff in there for a while.

[Trwhouse]

Hey there MJN12,
Can you take a photo and post it of what the petcock looks like now?
I'm trying to imagine what the previous owner did to it.
It would be interesting to see. Maybe we could come up with more assistance if we can view it.
Thanks,
Todd

[LimaXray]

You probably should look into getting some kind of petcock, at least for the purpose of shutting off the fuel when it's not running. 

As Jenya said, the float valves can get stuck open for whatever reason (such as a small piece of dirt from the fuel tank gets caught in the valve seat).  If this happens, it will result in one of 2 outcomes: 1) the fuel flowing out the back of the carb into the airbox and out on the ground or 2) flowing out the front of the carbs into the cylinder.

1 just makes a big mess and possibly the need to walk to the nearest gas station to get more gas.
2 can cause the engine to hydrolock when your try to start the bike and the liquid gasoline that now fills the cylinder doesn't compress.  This is very very bad

In reality, the chances of this happening are pretty small, but big enough for just about every carbed bike to come with a petcock from the factory

[mjn12]

Hey there MJN12,
Can you take a photo and post it of what the petcock looks like now?
I'm trying to imagine what the previous owner did to it.

The petcock is just gone.  The primary and reserve tubes leave the gas tank, and connect to each side of a T shaped tube which is connected straight to the carbs.  no vacuum tube to be found.  According to what everyone has said I should be alright as long as I don't let it run out of gas although I risk spilling some fuel and the small chance of hydro lock. I'll probably buy a replacement once the cash is available and throw it on there this winter. I'm not gonna stress out about this one.

I'm also dealing with what sounds like another pretty common problem with my bikes idle randomly jumping to about 3~4k after I realease the throttle and pull in the clutch.  I can hear and see the throttle snap back into position around the carbs so I don't think its a sticky cable. I'm guessing the carbs just need cleaned.  The PO said he had done this recently, but I don't think I trust him too much and after looking at them closer they're kinda grimy on the outside so I can't imagine they sparkle on the inside. I'll probably pull them as soon as my bike cools and clean them tonight to see if it helps me out any.  Someone stop me if you dont think this will fix anything.

[scottpA_GS]

You probably should look into getting some kind of petcock, at least for the purpose of shutting off the fuel when it's not running. 

+ 1

You deff. should have a way to shut off the fuel 

Oh and does anyone have an extra petcock laying around -- I supposed I need to buy one.

Ive got one... $15 Shipped 

Its used but in good condition.