Gas Cap

[Morgan Scout]

Having troulbe with my 1964 Scout 80 after fueling. Seems starved for fuel. Does this model require a vented or non-vented gas cap. Mine is non-vented.

[Bill usn-1]

Depends on the filler hose.
If original then there should be a vent hose that comes off the top of the filler hose to provide a vent.
If it has been replaced by the previous owner then it may not have the vent hose in it.
Go to IHonly north or superscout specialties to see what the right one looks like.

[Jay Tabor]

easy enough to find out, of course all those old vehicles were vented fuel systems .. but never mind . .
stick a piece of paper or a small stick between the gas cap rubber seal and vehcile body and drive the vehicle, look listen for improvements.

[tdc]

Originally Posted by Jay Tabor

easy enough to find out, of course all those old vehicles were vented fuel systems .. but never mind . .
stick a piece of paper or a small stick between the gas cap rubber seal and vehcile body and drive the vehicle, look listen for improvements.

This thread popped up when I searched vented / non vented. Hopefully the OP got the answers he was looking for.

Adding to it, not hyjacking it;

When I pop the gas cap on my '75 SII, I get a rush of fumes coming out. Is that normal?
It has a 1979 SII gas tank, vent hoses, same as the 1975 emissions.
Would a 1979 charcoal canister system to vacuum port on carb relieve the pressure, or should I just not worry about it?

[Doc Stewart]

If the truck is running well, don't fuss with it.

[jauringer]

Originally Posted by tdc

This thread popped up when I searched vented / non vented. Hopefully the OP got the answers he was looking for.

Adding to it, not hyjacking it;

When I pop the gas cap on my '75 SII, I get a rush of fumes coming out. Is that normal?
It has a 1979 SII gas tank, vent hoses, same as the 1975 emissions.
Would a 1979 charcoal canister system to vacuum port on carb relieve the pressure, or should I just not worry about it?

Vented gas caps only cure vacuum problems, not pressure. I developed the same issue and while it didn't cause any problems, there was a lot of pressure building up. I drilled a small hole in the one way valve on the cap to vent both ways, but idealy, It would probably be better to get a vent working properly.

Jason

[tdc]

Originally Posted by Doc Stewart

If the truck is running well, don't fuss with it.

Alrighty then. Thanks Doc.

[tdc]

Originally Posted by jauringer

Vented gas caps only cure vacuum problems, not pressure. I developed the same issue and while it didn't cause any problems, there was a lot of pressure building up. I drilled a small hole in the one way valve on the cap to vent both ways, but idealy, It would probably be better to get a vent working properly.

Jason

The saga continues. Thanks J.

[Jay Tabor]

easier to push an awl thru the gas cap neoprene seal/gasket, makes a tiny hole and vents the gas tank.
or next time youre in the auto parts store . . . ...

[tdc]

Originally Posted by Jay Tabor

easier to push an awl thru the gas cap neoprene seal/gasket, makes a tiny hole and vents the gas tank.

That works. Just that small amount of air space was enough to vent, Thanks Jay.
I tried the flat side of a zip tie between the cap and filler neck, then driving and there was no difference in start up or performance.