So I rebuilt my engine (1200 conversion) and noticed the petcock was leaking gas. There's the fuel line in the front that goes to the carb. another smaller vent line in the back, and I noticed drops of gas leaking from a hole inbetween those two lines.

I could be wrong, but it looks like a weep-hole. It sticks out, but not enough to clamp a hose on it. What the hell is this???

I have the service manual...doesn't say anything about it.

 

Anyone?

 

I can't say for sure how the harley vacuum petcocks are, but my kawasaki had a vacuum petcock, and it had a extra vent hole, to allow air at the back side to allow the valve to pull in to allow the valve to slide over. And by the way, that second line is not a vent line, it's a vacuum line that goes to the carb, basically if the engine is not running the petcock will not open even though you have the lever turned on, it needs a vacuum from the intake to open the valve. I've yours is leaking fuel, you can get rebuild kits for it, or you can simply replace the petcock. You can replace it with a non vacuum petcock if you want, but then you need to plug the vacume line from the intake. Vtwin sells OEM copy petcocks that have better seals than the harley ones use, or if you got money to throw around you can get a Pingle petcock, but their expensive.

 

The petcock has an outlet for the fuel line and another which should be connected to a vacuum line from the carb. Other than that, I don't know what to tell you other than you've got a bad/leaking petcock.

 

The diaphram in those vacuum petcocks develop leaks and then the fuel leaks.

You can drain ALL the fuel from your tank, remove the petcock, disassemble it and replace the diaphram, P/N 27361-76A. It is easy to do.

I disabled mine as I don't feel I need to be saved from myself and now there is one less part that could leave me stranded again. But you gotta do what you gotta do.

 

I agree! It is a simple fix and I gutted mine too and it gives you peace of mind to know that you have eliminated a possible problem before it became one.

 

you have a bad diaphram. I would change the petcock out for a nice chrome one that isn't a vacume type, that way on long uphill climbs when passing, the fuel will not shut off. I've had it happen.

 

Does anyone know the first year that they started using those vacuum petcocks on Sportsters. I know the 92 didn't have it and the 96 did, but I'm wondering what year they first appeared on Sportsters.

Thanks.

 

I think 96 was the first year, i think that's may also be when they switched from a voes switch to map sensor also???. Anyhow I have a 94 and it didn't use a vacuum petcock.

 

or was it 04 for the map sensor switchover with the rubber mount engines??