Fuel cap issue?

Not surprised you knocked it over. Must be tricky getting out of the wheelchair and onto the bike.
 
not sure if triples cap is different from a twin, but I cut a sheet of fel pro gasket material to replace the old gasket on the cap and inserted a rubber O ring gasket from an Aprilia Falco gas cap that fit perfectly into the gas tank neck - no more leaks from a full tank
 
Dellortoman said:
When I bought my Jota, the fuel cap had one of those rubber top hat things and it leaked heaps. I took the rubber thing out and the cap was fuel-tight. No more leaks.
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I guess it depends on which type of cap you have. I only have a problem if I fill up too high on a hot day and then it’s my own fault. I do think the rubber thingy stops fuel surging out under braking. But not when doing vertical stoppies.
 
For vertical stoppies, you would need one of those breathers with the steel ball inside. I had one, separate from my Aero fuel cap. It wasn't that helpful as it was so long it hung down into the tank that far it would self syphon if the tank was filled. That was even lower than the level where braking slosh caused a leak. It's not so easy finding a method to fill these tanks as high as possible. The 2 things I wanted was a fuel cap and a breather that didn't leak including if the bike was on its side. My Aero cap fixed one leak but I couldn't find a breather that fixed the other leak, the breather I have now has a floating ball that stops flow for overfilling but only the steel ball type fixes tip-over leaks. I Bet Paul would have liked that so maybe stop a fire from happening just from a tiny tip over. Huge tank impacts are another thing obviously. I learned something a while back, on modern fuel-injected bikes they cut spark on a tip-over and take approx 30 seconds to return the ignition to fire the bike, someone had a tiny crash on a wet 35kph bend and the bike wouldn't start till the ignition reset. Years ago I had a Bike burn to the ground, it focuses the mind to avoid it happening again.
 
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Again, the filler neck on a triple tank may be different from a twin, but this gasket from an Aprilia Falco gas cap I had on hand gives a perfect leak proof seal against the gas cap that I fit w/ Fel Pro gasket material. It fits snugly around the lip inner ring and doesn't fall out or into the tank. The other rubber plugs mentioned aren't designed correctly, and I found one inside the tank when I first got the bike.
 

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TeddyG said:
Again, the filler neck on a triple tank may be different from a twin, but this gasket from an Aprilia Falco gas cap I had on hand gives a perfect leak proof seal against the gas cap that I fit w/ Fel Pro gasket material. It fits snugly around the lip inner ring and doesn't fall out or into the tank. The other rubber plugs mentioned aren't designed correctly, and I found one inside the tank when I first got the bike.
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1972 on 750s and triples apart from RGS SFC 1000 have identical fillers.
Paul
 
Guys - there are (at least) two type of filler caps (one with a quite large metal part holding the gasket, one a bit smaller) and also (at least) two type of rubber inserts (one that looks like a diaphragm and one that looks like a hose with a gasket).

I have the smaller metal part filler cap and one of those hose-a-like inserts and the fuel tank is fuel tight under breaking. I had the diaphragm-type one before and that one filled itself with fuel if you toped the tank up to much and under breaking, washed your whole frontend with fuel... exchanging the two fixed it for me.

I can make pics if anyone wants, as they may tell more than words...

HTH
 
Laverdalothar said:
Guys - there are (at least) two type of filler caps (one with a quite large metal part holding the gasket, one a bit smaller) and also (at least) two type of rubber inserts (one that looks like a diaphragm and one that looks like a hose with a gasket).

I have the smaller metal part filler cap and one of those hose-a-like inserts and the fuel tank is fuel tight under breaking. I had the diaphragm-type one before and that one filled itself with fuel if you toped the tank up to much and under breaking, washed your whole frontend with fuel... exchanging the two fixed it for me.

I can make pics if anyone wants, as they may tell more than words...

HTH
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Fill the tank and then lie the bike on its side to be sure.
750 SFC has a larger filler to get fuel in more quickly.
Paul
 
If toped up completely and then under hard braking nothing comes out of the filler-cap, that's enough for me.

BTW: was all discussed 6 years ago already:

fuel filler cap

Hi there I have small problem on my sfc replica. I bought new fuel filler cap and i noticed right away that fuel is pouring out when braking ,... Then i compared filler cap with original laverda filler cap on my 750 sf and i noticed that original filler cap seals to outside lip of the filler...
laverdaforum.com laverdaforum.com
 
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Laverdalothar said:
If toped up completely and then under hard braking nothing comes out of the filler-cap, that's enough for me.

BTW: was all discussed 6 years ago already:

fuel filler cap

Hi there I have small problem on my sfc replica. I bought new fuel filler cap and i noticed right away that fuel is pouring out when braking ,... Then i compared filler cap with original laverda filler cap on my 750 sf and i noticed that original filler cap seals to outside lip of the filler...
laverdaforum.com laverdaforum.com
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A lot of people new to the marvellous Laverda world in 6 years.
Paul
 
TeddyG said:
Again, the filler neck on a triple tank may be different from a twin, but this gasket from an Aprilia Falco gas cap I had on hand gives a perfect leak proof seal against the gas cap that I fit w/ Fel Pro gasket material. It fits snugly around the lip inner ring and doesn't fall out or into the tank. The other rubber plugs mentioned aren't designed correctly, and I found one inside the tank when I first got the bike.
Click to expand...
The gas cap in your photo looks nothing like the one I have, the Falco gasket looks interesting.

Laverdalothar said:
Guys - there are (at least) two type of filler caps (one with a quite large metal part holding the gasket, one a bit smaller) and also (at least) two type of rubber inserts (one that looks like a diaphragm and one that looks like a hose with a gasket).

I have the smaller metal part filler cap and one of those hose-a-like inserts and the fuel tank is fuel tight under breaking. I had the diaphragm-type one before and that one filled itself with fuel if you toped the tank up to much and under breaking, washed your whole frontend with fuel... exchanging the two fixed it for me.

I can make pics if anyone wants, as they may tell more than words...

HTH
Click to expand...
Yes, please post a few pics, thank you.
 
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