and i lost my fuel tank cap! Holy moly!

[Tauseef]

Yes, but not to the carburetor, just a separate line known as a breather, on motocross bikes it's extremely common as basically anything but a thin tube will let fuel splash out as you're jumping and swinging the bike all around. If you have spare carburetor parts (or an old pen you aren't fond of) you can drill a hole in the cap and stick a fuel nipple or pen tip with super glue and put a line off that.


It shouldn't cause a fire, no, no more so than any vented cap would if you brought fire near it, but that's the nature of gasoline, not gas caps. Just don't drill it with the cap on the tank since sparky tools make gas go boom boom.

Boom Boom! Hehehe

Thanks for this advice/reminder

 

[Tauseef]

So based on all the concepts/tips/examples in this thread,

I took a brass connector,
And i place a 0.5mm tube on its end,
And filled the end with hot-glue .
So now ,brass connector is 0.5mm vent.
I placed rubber pipe over this,
And at the end of rubber pipe placed a plastic with hole in it ,fixed with hot glue.

Any flaws?

Quick question : is hot glue compatible with petrol?

 

[FurryOnTheInside]

Any flaws?

Quick question : is hot glue compatible with petrol

The PTFE Teflon tape might shred or unravel. The tube might be PVC and might harden and crack.. I guess you'll find out though.

I assume that it is. I had a leak in my plastic tank where it's plastic nipple wasn't sealed to the tank itself, which I fixed by mashing the plastics together with a soldering iron then mashed hot melt glue into the surface, then put JB Weld over that. One of those things has sealed it.. I guess you'll find out though.

 

[CrazyDan]

Looks great. If the current tube fails use gas line.

 

[Frankenstein]

Looks great. If the current tube fails use gas line.

Wtf looks great, I hope you don't mean the big ugly piece of ziti pasta (yes I'm aware of what looks nice no matter how little I care about looks in actuality.) You just like that he used your nipple idea.

I would have stuck with just the brass and the very small hole, maybe up it to 1mm since I don't know if half a mm would let enough air in quickly enough. I think I know where he was going with his idea, of so I'd just glue it from the inside with the majority of the nipple being empty and unfilled, then drilled (or preplaced) a hole in the glue, this way any ultra tiny drips or bubbles wouldn't be able to excape the last half inch of brass nipple.

 

[CrazyDan]

Looks like a fully functional breather tube made out of stuff he found around the house, so it looks nice to me.

 

[Frankenstein]

Looks like a fully functional breather tube made out of stuff he found around the house, so it looks nice to me.

At least put a bright yellow flag to make it match the rest of the bike!! Oo or wrap it in that reflective tape, orange white and red, and reflective cylinders reflect light well from all angles, and so are a bit brighter at night when light from sources other than from the driver's vehicle can light up the post well enough to be seen.

 

[Tauseef]

Wtf looks great, I hope you don't mean the big ugly piece of ziti pasta (yes I'm aware of what looks nice no matter how little I care about looks in actuality.) You just like that he used your nipple idea.

I would have stuck with just the brass and the very small hole, maybe up it to 1mm since I don't know if half a mm would let enough air in quickly enough. I think I know where he was going with his idea, of so I'd just glue it from the inside with the majority of the nipple being empty and unfilled, then drilled (or preplaced) a hole in the glue, this way any ultra tiny drips or bubbles wouldn't be able to excape the last half inch of brass nipple.

hhaha

I did not feel "safe" without tube covering the nozzle.

 

[Tauseef]

At least put a bright yellow flag to make it match the rest of the bike!! Oo or wrap it in that reflective tape, orange white and red, and reflective cylinders reflect light well from all angles, and so are a bit brighter at night when light from sources other than from the driver's vehicle can light up the post well enough to be seen.

Yesssss...there should be a flag

 

[Steve Best]

Tauseef, the brass plug is a good idea because it is non-sparking.
The teflon tape is not needed and not a good idea because it will contaminate and plug your fuel system.
The brass plug only needs to be finger tight to seal enough for this situation.
The breather hose and tube only need to be very small. Use the smallest available.
The MX "breather valve" is not especially needed, it is only a baffle.

I would suggest to use a longer smaller hose and tie it under the seat.
(Perhaps a hose that fits inside the barb, with a clamp inside the tank so it will rotate?)
This would keep the gas cap from ever falling off and getting lost again.