Vacuum Tube on Throttle Body?

[PetieJ]

I have just been looking over the scoot and found something that has me wondering, "Whats-it?". It is located on the throttle body behind the air filter. My guess is some type of vacuum line used for testing. The problem I see is that the small rubber cap over this line is deteriorated and may not be sealing whatever it is suppose to seal. What is purpose of this line/tube?

2003 Softail

I have attached a pic of the line and rubber cap.

 

[tyre]

I can't tell you what is 4, but I would make sure it doesn't leak with a new one.

 

[PetieJ]

I have not noticed any problems with running, which is good, but I can
find no reference to it in the service manual.

 

[tyre]

Like with some elect plugs that go to now where./ test ports or to plug in a metering tool . This could be for a vaccume gage test.

 

[RibEye]

It has to do with some California-required fuel vapor elimination. Most of us don't have anything connected there. I think it connects to the fuel tank on California models.

Enjoy,
Rich P

 

[PetieJ]

Thanks RibEye. Something like fuel vapor recovery I reckon. It is now plugged no matter what it is. Figured it had some function for somebody.

 

[harley@16]

I would make sure there is no vacuum on it because if it leaks it will cause a lean air-fuel ratio