I'm working on a 2006 Softail Deluxe TC 88 for a friend.
It cranks fine, has spark but isn't starting, guessing this is a fuel problem.
I pulled off the fuel line at the carburetor turned on the petcock and got nothing, regular or reserve.
This with the key off (and obviously engine off), but ... it isn't starting right now anyway.

There is what looks to be a vacuum line attached to the top of the petcock.
I'm assuming that this line must have vacuum from the carb in addition to petcock being ON or RESERVE to allow fuel through.
Guessing this is a safety feature? shuts off fuel when the engine isn't running. If anyone knows its real purpose would be helpful.

Anyway ...
First question is does the carb create enough vacuum when cranking to allow fuel through?
Second question is there an easy way to test this to see if some small vacuum allows fuel through.
(I tried using a baby snot sucker to create a vacuum on that line and then blew through the petcock ... no luck.)
Third question is should I keep this petcock or dump it and buy a standard on / off, or something else completely different?

Any helpful advice would be appreciated :-)


Looks like a vacuum bellows to me

Top is fuel in, facing is fuel out to carb.

Front view of the carb for ID purposes

Little black line behind the carb is where the vac line attaches.

 

Two things
That thing you have off and laying there is a vacuum operated petcock and sucks
.Generally they will not let much gas through unless the engine is cranking over/ or running.
Sometimes they just quit and don't let any gas through.
Toss it in the trash.
Next with a real petcock installed, you should see fuel squirt into the carb from the accelerator pump when you wick the throttle .

 

yes, you should replace it with a good one like this ....

but for now ...try filling the carb with gas too be sure it will start ...will need to plug off the tube coming from the intake ...to stop the vacuum leak ...will need to plug it for good if replacing petcock with new pingel ...

 

Exactly what it is. Just in case you forget to turn off fuel, it does it for you. Safety. Do not take it off. When carbs get old, they leak a little and sitting overnight will flood the floor. Running, it can be fine.

When you crank it, it will pull a vacuum to open it unless it's bad. Put a hand test vacuum pump on it to check. If it is bad, replace it.

Hit it with some starting fluid or a few drops of gas. See if it tries. Be careful and not too much. It can spit back

 

You like to be stalled in cold dark lonely places too.

 

There is no reason a valve has to be any more complicated than need be. More things to fail. Replace it with a Pingel.

Remembering a valve when you get on and off isn't a big deal.

 

If the needle seat is in proper shape it will not /leak.
The old carbs as in Tillotson, links, Bendix were prone to stuck needle seats.
They would leak all over the place once in a while.
Even the first generation Keihin in the middle 1970s ( non CV) did.
I have not ever had a CV leak overboard.

 

Thank you guys for all the feedback, will talk to the owner and let him decide.
Sounds like it's nice to have but not 100% necessary if you remember to shut off the gas every time.

If he buys a new safety valve, will make sure to rebuild the carb and replace the hose between as well.
Otherwise he gets a "remember to turn it off" warning and I take out a small insurance policy :-)

 

My mechanical religion says get rid of anything that might cause failure.
The nuance for a vacume operated shut off was invented by govt.
No one would purposely install such a POS on a bike unless they were trying to cover up a problem.
In the old days, I used to shut off the petcock...Had too.
Since the advent of real tolerances, I have got lazy .
I dont shut off the Pengal anymore.
Never ever had a problem.
I sure did with the dam vavume operated crap.!