Petcock confusion.... CB550

[Shooter]

CB550 '76 (but maybe '77)

I have got my self confused over what position the petcock should be set to and I am now not sure if the arrow and the markings are correct.

Confession - I ran out of gas over the weekend.

I think I must have had it set to reserve and run a whole tank through at that setting because when I switched to what I thought was reserve position there was "nothing left in the tank" (as the saying goes !)

I am thinking somehow I have set up the petcock wrong when I totally dissasembeld it and replaced the filters with a kit. (Is this even possible? )

I know they changed the position at some point around 76/77.

 

[buzz286]

you only have 3 choices,,off.main.reserve...attach a fuel line,,,,guzzle or puff,wait and watch what happens, and let it dump into a can

 

[Shooter]

Off is easy....but it seems in my case that if the arrow points downward at the 'ON' label...I can run the tank dry.

Surely this should only be the situation if I had the arrow marking pointing upward at the 'RESERVE' label.

I do not want to have to pull the petcock assembly out of the tank to see if I assembled it wrong (if that is even possible to do).


Draining the tank as a test proves nothing much.

 

[dgfischer]

I do not want to have to pull the petcock assembly out of the tank to see if I assembled it wrong (if that is even possible to do).

The petcock has a brass tube that sits inside the tank for the "ON" position. The opening in the top of the tube sits about 3(ish) inches higher than the bottom of the tank. Fuel is drawn through the top of the brass tube untill the fuel level has dropped below the top of the tube and can draw no more fuel. This is when you would switch to "RES"
"Res" draws fuel fron the bottom of the tank.

It is not uncommon for the brass tube to get broken off or have cracks in it, allowing it to completely drain the tank when placed in the "ON" position. You'll have to pull the petcock off to check the condition of the tube in the petcock.
DG

 

[Ease]

The petcock has a brass tube that sits inside the tank for the "ON" position. The opening in the top of the tube sits about 3(ish) inches higher than the bottom of the tank. Fuel is drawn through the top of the brass tube untill the fuel level has dropped below the top of the tube and can draw no more fuel. This is when you would switch to "RES"
"Res" draws fuel fron the bottom of the tank.

It is not uncommon for the brass tube to get broken off or have cracks in it, allowing it to completely drain the tank when placed in the "ON" position. You'll have to pull the petcock off to check the condition of the tube in the petcock.
DG

Yeah I'd just pull the tank and check it out. Not too much trouble really.

Someone on here might even be able to point you in the right direction to get yourself a rebuild kit (or your dealer for the tube if it still exists).

 

[Shooter]

I am figuring that when I fitted the new filter kit in the petcock (6 months ago) that somehow the brass riser rod may not have been present. I do not remember seeing one although it is how I figured it worked.

Guess I have to pull it to find out.

Thanx for the help. Exactly what I needed to know.


EDIT : riser tube does not show in the parts manual diagram for some reason!