Okay, so I finally got around to rebuild the petcock on my girlfriends bike, and here's the walk through for you all:



First off, what is the petcock? Well you can see it clearly here on the bottom of your tank. It's the fuel on/off/reserve switch, and it's a fairly simple device. It however is vacuum operated, or more like it won't allow fuel to flow unless there is appropriate vacuum. This comes in the form of vaccum created inside the engine cylinders,and when they pull air in through the carbs, they also are creating a vacuum (sucking air) from the petcock to allow the fuel to flow.



So first off, draining the gas. You can do this a variety of ways, but the method I liked to use was hooking up a vaccum hand pump to the petcock, running fuel line into a fuel container, and creating vaccum. This causes the petcock to allow fuel to flow. Now, if your petcock is completely shot, this of coruse won't work, but I've seen that most petcocks don't fail all at once, they fail partially. You should be able to make this technique work, even if it's not an ideal flow.



Next up, remove the petcock assembly from the tank. if you can't figure this one out, you're stupid and should hire a mechanic instantly. I'll give you a hint though... undo the giant nut that is the only thing holding it to the tank.



So here we have the petcock on the left, and the rebuild kit on the right. The rebuild kit on the right was purchased from SDS performance. You can email them to order the kit yourself: sdstigard@gmail.com



Now this is the most important part: Installing it all in the correct order! I've already completed the job at this point, but I took the old parts and placed them so as you can see the order for yourself! PLEASE only refer to this as a last result. This should be a VERY simple process if you take the petcock apart slowly and pay attention to the order in which the original parts went.

The small diaphragm goes on the left, and it's nib connects to the metal cylinder. The metal cylinder goes through the hole in the mid plate (big plate being held up by the needle nose pliers). On the other side of this, you plug the nib in for the large diaphragm. From there, you place the hard small plastic plate, with the spring on it, and finally the last plate where the vaccum itself is applied.

Below are some pictures detailing the order.

(NOTE: In the middle three pictures it should be quite clear that the large diaphragm is warped and beatup. This was the cause of needing to rebuild my girlfriends F2 carbs)

 

Awesome howto! Thanks for taking the time to write that up. :thumbs up

 

Thanks. Now to see if it becomes a sticky or not.

 

*BUMP*

A bunch of people found this thread and got in touch with SDS performance to dig up the petcock parts. They've still got a good line on these parts, so if you need them, get ahold of them!


Also, whose dick do you have to suck around here to get a post stickied?

 

Alright, nobody runs this place I guess. Time to post up some **** or something

 

JesseAwesome

My buddy was trying to get his 91 CBR 600 up and running again after 8 years. We were not getting any fuel from the tank and could not find a good diagram.

From the bike siting for 8 years, the most inside diaphragm was basically glued to the metal housing. So thanks to you, have another rider on the road!