Cleaning up vacuum lines. By netmare (Read 1,719 times)

[netmare]

I want to remove all unnecessary vacuum lines.

I will keep the carb line.

I am switching to a manual petock.

My conundrum: What to do with the gas tanks vapor tube. The one that goes to a one-way valve and then on to the emission system canister (which I want to remove).

So far any kind of vapor lock has not been an issue. My gas cap is not ventilated.

Could I just seal it up and just remove the gas cap every now and again?

Thanks.

cg

(I posted this over at Scootdawg's also)

[Bashan]

I think removing all unnecessary vac lines and going to a manual fuel valve is a great idea, I did it a long time ago on my Bashan. It removes a lot of potential leak sites and gets rid of that accident waiting to happen vacuum petcock/fuel valve. You could loosen your cap once in a while but you'd be doing it more often than you'd like, I've been there. I'd say the best option is to get a vented cap, however, I should take my own advice since I've yet to do that. I took the vent line coming from the filler neck and made an upside down "U" with it to trap vapors but provide a vent. Gas vapors sink, look at the warning label on your gas water heater if you have one, so they don't make it over the "U". Here's an article on what I went through with my Motorino that you might find of interest. Rich

[netmare]

Thanks for the response Rich! I had you until the "U" thing. I'm a picture person, mostly. I was thinking of drilling a 1mm hole in the top of the cap. Off of the tank, of course! Sound good?

Thanks again!

cg

[jct842]

I have owned a 1952 ford 8n for 15 years. 14 years I had to loosen the gas cap every now and then when the engine would start faltering. I finally had enough and drilled a 1/16" hole in the top of the gas cap never to be bothered again. have never had a drop come out either and a tractor has a whole lot more sloshing and bouncing around than a scooter would on the street. get your drill out! john

[netmare]

Right on! Thanks John!

I will do that. My only concern, is that the cap is enclosed within/under the seat. The bucket area may smell of gas, but it does have an escape. More or less just a preference, not a concern.

cg

[Bashan]

Here's a diagram of my Motorino gas tank, it is the oddest shaped thing. There was actually a mount under the floorboards for a gas tank and a filler cap door in front of the seat! Why they chose to put this bizarre gravity feed system on I'll never know. The problem was the long filler neck with the vent tube at the bottom. A little too much gas and it ran down to the check valve. Here you can see the representation of the upside down tube that I installed after removing the vapor system:

So that you won't think I'm exageratting, here is an actual picture of the tank outlined in red. You can see the upside down "U" vent hose with an old fuel filter I stuck on the end just in case some slopped over;

[netmare]

Thanks Bashan. With my tanks setup, the clearance is very tight. I think I'm gonna plug it completely and drill the cap. I never fill my tank all of the way. There's a brace in there I fill to. I don't know what the volume is, but the gauge reads full. Either way, I work only 3.5 miles away. I'll post with the results after I get to that mod.

Thanks for the advice.

cg