Topic: Fuel system questions

[Kinch]

Hello, I'm troubleshooting a possible fuel flow issue on my 1975 CB750 K5. I recently took apart and cleaned the petcock but the gasket under the plastic petcock filter came apart when I tried to remove it. Does anyone know where I'd be able to find that gasket without having to buy a new filter set?

I was thinking about just exacto-knifing a makeshift one but I'm not sure what kind of rubber I could use that wouldn't be melt and come apart.

Also, does anyone have a diagram of the best way to run the fuel line from the petcock to the K5 carbs?

Thanks

[manjisann]

Not sure how much help it is but the orings and such that we use are made out of Nitrile (sometimes called Buna N). I am not sure if it comes in sheets or not.

Brandon

[Kinch]

Thanks

[manjisann]

NP, actually, do you have a pic of what fell apart? I bought a rebuild kit for my CB500 and it had a rubber gasket with 4 holes in it in a circle, is this what you are referring to? If so, what size was it, if the one I have will fit, I'd be happy to send it to ya for the price of postage.

Brandon

[Kinch]

Sorry about the delay, it's the rubber gasket that sits underneath the plastic filter (the exposed area showing in the picture) and it's a circle with a small section cut out. I think it only had 2 holes if I remember correctly.

[tlbranth]

I've bought sheets of Gasket material from Auto pars stores and one pack I got indicated what the various materials could handle.

[manjisann]

  The one I have has 4 holes in it, so it probably wouldn't work. My petcock had two gas lines running to the carbs, this one looks to only have one. You might be able to fab one out of the material, other than the ones that are manufacturered have ridges around the different circles and the outside diameter of the gasket itself.

You can check eBay, someone might be selling just the little gasket you need. Sorry, wish I could help.

Brandon

[Kinch]

Thanks. I cut one out of thick balloon rubber just to put it together temporarily and test everything and it still leaks. I cut the rubber to pretty much the exact shape of the old gasket and while I wouldn't go driving the bike around with it like that it will have done its job for a short while at least so I don't think that gasket is the problem.

I think I'm just going to get a replacement petcock from Z1 at this point and stop messing with it.  

[Kinch]

Yeah, mine only has the one valve. Thanks for offering to help though.