petcock confusion

[williamemack]

Twice now, I have run out of gas. Mine is a 1980 R65 and run is when the lever handle is down(south), off is when lever is east or west, and reserve is north...at least that's what I think and it seems to be what my owner's manual sez. What happens is I begin to run out, I flip the lever to north and I seem to get no additional didtance. Tonight, I took the gas line off below the petrcock, put the lever at south and let the fuel drain into a gas can. When I ran out, I switched to north and I DID get more fuel, so reserve tube seems to be in place and free nof blockage. Any ideas

Any forum member riding around Squam Lake(NH) is welcome to stop when they go by.

[weasel01]

I think there is a part of the tank that holds fuel but cant flow because of the tank shape.

Did you try to lean the tank way over? I've heard this works but fortunately have not run dry ...yet.

I reset my trip meter when I top off and roll about 175~190 mi. then refuel and reset.

[Bob_Roller]

Have you kept track of about how many miles to reserve ?

[Justin B.]

I can only think of three things that might cause this:

1.  The reserve channel in the petcock may be clogged.
2.  Somebody has removed, cleaned, and reinstalled the petcock with the "straws" reversed.
3.  The long "straw" for the "main tank" is missing.

[Bob_Roller]

Will mentions that it has happened twice, is this a recent development ?

I think I would remove the tap from the tank, and take a good look at it , especially if you are not the original owner, there have been reports from non-original owners, that they have found the intake tubes on the tap, cut down, or otherwise altered to try to get more of the 'unusable' fuel.

[DgM]

You might want to check the fuel cap, as it contains the vent to allow air to replace used fuel volume.  My 1983 R65 engine would stop, I'd open the cap to see how much fuel was inside, then it would run again...

[Barry]

Will

What symptoms do you get when running onto reserve ?

 When I switch to reserve it  can take quite a while before the engine picks up again. Maybe something to do with limited breathing through the tank filler cap.

You should be able to see if the short and long tubes are in place by looking through the filler with a slim torch.  The tubes are just a push fit in the petcock.

[Bob_Roller]

The intake tubes on my fuel tap, appear to be in some sort of red epoxy looking material around them, they don't come out .

[Justin B.]

The ones I have messed with have had "removable straws".  Maybe your's is a newer tap or has been "improved" by someone...

[Bob_Roller]

No, I'm the original owner, and the bike was only back to the dealer once in 1982 for an oil pressure problem, so no-one has worked on the bike, except myself, since purchasing it new in January, 1981 .

The fuel tap, which is the original, has been removed fom the bike three times since I've had it .

[Justin B.]

Damn!  The cheap ba$tards have always gypped me, then!  They keep this crap up and I'll go and buy a jap bike...

[drewboid]

I've seen metal straws and plastic ones. Both were press fit into the body of the tap. Both types can come loose and the plastic ones can crack with age. It usually takes a few seconds (sometimes VERY LONG seconds) until the reserve position can refill the carb bowls and the bike start running again.
Although you did get flow from the reserve position it may be good to check that the flow rate is adequate to run the bike. There may be sediment in the reserve position ports and not enough fuel flows.
When you looked at the straws were they of different lengths? (I know - dumb question but I have to ask).

[steve hawkins]

What you also have to appreciate it that it is a gravity system with a very little head of fuel - i.e. weight of fuel pushing down, when you need to switch to reserve.

If you any extra restricions like old after market filters in the line, you be affecting the rate of replenishment of the fuel in the carb bowls.

One of the reasons, I prefer to rely on a good working fuel tap and not put in any extra fuel filters in my lines.

I also prefer to flush my fuel tank out every year or two, to remove anything that should not be in there, rust, water, and anything else the petroleum companies want to be rid of.