Special petcock replacement?

[dbbrian]

My petcock rebuild isn't successful (yet?). The bike runs fine, but I took my tank off after a ride and when I unhooked the fuel line on one side the gas poured out. Other side fine. Double checked and it doesn't seem gas was getting past the carbs and into the crankcase.

Switching the petcock to prime stopped the flow. Switching the other side to prime didn't start the flow. So something wasn't put together correctly, and I wonder about that little brass valve working on the one side (previous post above). I thought I was being careful to pay attention when dismantling but maybe not careful enough. There are tiny holes in the casting, the middle plate, and the rubber flaps. Hard to know if things are properly aligned. those rubber and centre plate pieces could each be positioned in 4 ways

Does anyone have a good clear picture of how the parts are supposed to align when assembling?

The alternative is to abandon and use non vacuum type, I guess add filters below? Already spent $70 CDN on the rebuilt kit

[oldyam80sg]

That's a lot of parts.I still have the original petcocks from my 80 SG but am not going to take them apart. Filters were removed a long time ago as they were bad.

[red bandit]

Sounds like you might have the turn handle from the left petcock on the right petcock. Try switching the turn handles.

[bikerphil]

Does anyone have a good clear picture of how the parts are supposed to align when assembling?

Rebuild video of a similar vacuum operated tap, 8:45 time is where the diaphram assembly starts.

https://www.youtube.com/watch?v=uIpEbkFd8mg

[dbbrian]

Rebuild video of a similar vacuum operated tap, 8:45 time is where the diaphram assembly starts.

https://www.youtube.com/watch?v=uIpEbkFd8mg

Thanks, saw that. Different petcock. No pegs to align, or opening at side of spacer on mine

[bikerphil]

I'll look thru my stuff and see if I have one I can disassemble.

[bikerphil]

This is a right side. As for the diaphragm, just line up all the holes as close as possible, the tap body, the plastic spacer, the rubber diaphragm, and the cap.

[dbbrian]

Bikerphil - thank you for that picture. I thought you were on to something but mine checked out same as yours, and after studying the connecting pathways in each position it made sense to me that the right side was on the right side.

What I did find upon disassembling was some white crumbly gunk that probably was casing the diaphragm to stick open. I think the white gunk is from water in the fuel at some point. So another round of cleaning, and also a bit of expanding the spring and reassemble. No gas running out in "on" position or reserve, but unfortunately not in prime position either. I can't make sense of that yet.

So, a mystery not completely solved, but the bike runs and the gas isn't pouring out in normal "on" position, so I'm moving on with my life hoping that the gunk didn't make it's way further. So far OK. I'm due for a carb clean - next chapter of bike maintenance.

[bikerphil]

No problem Brian. That is strange what you are describing with no prime flow on that one side. The gas shutting off when it should is good though and now you can continue riding and enjoy the summer.