[ecka00]

I'm doing a little maintenance on the bike and want to be able to run the engine while the tank is off the bike so I purchased a 4' long fuel line to run to the carb from the tank. The 3/4" fuel line is all that I attached (not the reserve or breather line). I made sure that the tank was elevated and that their was no dip in the fuel line to the carb. Well it didn't work, in fact when I took the line off there was no fuel so to test my theory further I pulled the fuel line off all together and opened the peacock and still nothing. What's the deal? Does the breather line pressurize the tank and force fuel through the line or do I have something blocking the peacock inside the tank? Any ideas\suggestions?

 

[LRCXed]

No, there's no pressure built inside the tank. You have a vacuum operated petcock if I'm not mistaken with your 81. You need to add a vacuum line to the front small fitting on the petcock to open it up so the fuel will flow. You can test that by putting a short hose on and suck on it to see if it opens it up.



If not, the screen inside might be clogged.

 

[Allan]

The 3/4" fuel line is all that I attached (not the reserve or breather line).

There is no reserve line,,that is a vacuum line, you need a hose on it that runs to the right side carb(right if you are sitting on the bike). There should be a port on the inboard side of the carb near where it hooks to the intake(engine side).



vacuum hose diagram.





BTW,,it is a petcock,,I think it is short for petrol cock,,sounds like a Brit thing to me,,basically it is a gas valve.

 

[ramprat06]

PETCOCK.....exactly. Vacuum or not, it still works. Let's hope.

 

[marshallf3]

I call it that darn thing I keep forgetting to turn off once I'm done riding. Getting better though.