HT leaking petrol/fuel cap

[fetor56]

I've sent Warren an email with an attachment:
"Warren....i'm working in conjunction with MBc(MotoredBikes.com) to find a solution to the petrol tanks leaking fuel cap.I would prefer a lockable cap and am prepared to pay for the whole mechanism myself(cap,plus filler nozzle)
I was hoping u could help me with a free(or loan) tank(without cap)
I'm sure i'll be successful and i'm happy to post pics and supply a full explanation on your website...credit where credits due.
If your interested to see what i'm talking about please register and view this thread: http://www.motoredbikes.com/showthread.php?t=8960
Regards,
Jack."

Let's wait and see what he sayes.

 

[BoltsMissing]

That is some fine initiative to attack the tank as you did Large.
Hope it works out whenh the goo dries up.

I been looking at the spare tank and cap.
Mine has not leaked yet, but if/when it does I think the source is the rubber seal on the cap.
With each turn of the cap to remove or replace, that seal wears a fraction and as the seal hardens in due time, then it becomes ineffective and causes to leak.
I think we simply may need to focus on replacing the rubber seal and in due time I hope a new cap design is not one that when tightened it twists on the actual seal.
I have some Castrol Rubber Grease GRR(B) and will smear a dab, hopefully to prolong the life of the seal.

 

[Large Filipino]

I'm having some leak issues right now I should have used a hole saw to a drill instead of tin snips but the gasket in a tube material is to blame. I'm gonna do this over with a more silicone based or I may even use that tank leak putty used in automotive applications. This morning it's not leaking around the ring but is leaking from the top screw. It's because I took off a little too much sheet metal in that area HOLE SAW remember HOLE SAW.
I didn't ride at all yesterday and I'm free today for my client is on a home visit so I'll just take off that top screw today and dab that hole and go riding. Tomorrow when my client is at home anyway so I can't go riding I'm gonna redo this seal.
I'm not too concerned about it. I KNOW I can seal her up. Then when it's all sealed up I'll do that overnight test with the bike laying down. I bet I'll get some gas from the carburetor from the tilted float bowl,but I'll keep the petcock shut off.
So stay tuned till tomorrow! I'm off into the vast ...known...don't want to venture too far off today.

 

[will_start]

Sealing the Gap.

Sorry to have to quote myself, but no-one's replied to this.

ok, I have two things to add to this.

2. I met someone who said you can run a bead of silicon inside the cap
then, put it on the tank, so it moulds to shape (tack dry time),
then take it off and let it set.

this apparently worked for this guy on several motors etc that he owns.
So I figured I'd try it one day on a spare cap I have.
If I get to it I'll post my results.

WS.

What do ya think, is there a way that this can work ?
That way we don't have to throw away the cap !!

Here's an extension on the idea.

2A. I thought I could cover the tank with plastic cling wrap
ordinary kitchen variety.
OR
2AA. Add a layer of vasoline to the tank or plastic, to prevent the sealant sticking. The original Idea, use vaseline to prevent the silicone sticking to the surface.

2B. Then put the silicone in the cap covering
the seal quite well.

2C. Put cap in the tank.

2D. Leave the cap in there to dry for
as long as your silicone instructions say.

2E. Then, pull out cap.

QA1.
Dunno how to get the plastic cleanly off the inside of the cap ?

Hmm have to think about this repair to make it really work.
I also don't know if silicone is not affected by petrol.
IE It can "melt" with petrol contact and get into the motor
and cause harm, over time ?

QA2.
Also, is a gap needed between the seal and the inside edge of the cap,
to allow the tank to breath.
Maybe some pin holes in the silicone would fix that, but not allow fuel through.
QA3. I will be testing the glue preventioness of vasoline on various surfaces, to prevent bonding with my variety silicone,
and also to kitchen variety plastic .

I'm checking this, before I do it, as I want to enjoy my motor
"once it runs."

Any comments anyone ?

BTW, That my $10(AU) x (each of us) saving idea
(that I took from someone else).
if it works.

CYA


WS.
I can feel another movie in the making with this one.

 

[Large Filipino]

I really think yes the seal but remember how I noticed my cap when it was locked I could "flip up" the corner?
I really think the sheetmetal that locks down the cap wears down in time and as the sheetmetal wears down the cap has less "spring" to seal right.
But you would think maintaining the cap with vaseline would make that bit of sheetmetal wear less if you put a little on the spring tangs on the cap along with the seal.
Everything those two spring tags touch when you put on the cap will wear in time.
I found some JB weld in a tube putty. It's made for underwater repairs and it says gas tanks so I'll give this a go. I noticed too I needed to flatten down the tank some so the filler neck would seal flush. It's not perfect but that putty should fill those imperfections and fill the holes.
I painted my tank so I'll wait till morning to sand and give it another coat then I'll install this again using only that putty.I also sanded both mating surfaces to the tank and filler for some "bite".
I think this time she'll hold.
You know,you could also just throw your entire cap into your used motor oil container from when you changed the oil in your car the other day.Let it sit there for a day.

 

[smitty]

To fix my leaky gas cap, I made a rubber washer out of a section of bicycle innertube, (punched a one inch hole in a 3" square of innertube) and stretched it around the under side of the gas cap. Then trimmed the outside (square) to the dimension of the top of the cap, and tucked it in to the top of the cap. then reinstalled the cap. It took about three minutes. The problem with this fix is that the rubber innertube is not gas proof and needs to be replaced periodically. I made several and keep them handy to replace when needed.
I'll try to post pics in a bit.

 

[smitty]

here's a picture. BTW don't take the original gasket out, just add the new one.

 

[Large Filipino]

JB Weld Waterweld is a white clay with the epoxy center that when you mead it with your hand it turns rock hard when it cures.It also says it's impervious to gas. I used the whole tube on my tank cause I wanted to ensure it would seal every crack and crevice. Then the excess oozed out while I tightened down the screws so I KNOW this is a good seal. I did away with the rubber gasket. I'm gonna let this sit overnight and then some cause I can't ride tomorrow anyway.
I also painted it,left the bottom half alone cause I think that looks cool that way. Then I had an excuse to use those cool clear stickers!

We'll see tomorrow afternoon how she holds up.

 

[will_start]

Smitty thats a great idea post some pics of how to do it. I have some spare inner tubes as well. goes with my motto of not wasting anymore money til it works, Large thats a great piece of work there.

WS.

 

[fetor56]

JB Weld Waterweld is a white clay with the epoxy center that when you mead it with your hand it turns rock hard when it cures.It also says it's impervious to gas. I used the whole tube on my tank cause I wanted to ensure it would seal every crack and crevice. Then the excess oozed out while I tightened down the screws so I KNOW this is a good seal. I did away with the rubber gasket. I'm gonna let this sit overnight and then some cause I can't ride tomorrow anyway.
I also painted it,left the bottom half alone cause I think that looks cool that way. Then I had an excuse to use those cool clear stickers!

We'll see tomorrow afternoon how she holds up.

Personally i don't think you've put enough effort into this Large...your gonna have to try harder man.
Tomorrow ya reckon....hopefually tomorrow you'll be the first person in the world(as far as we know) with a non leaking HT tank.................good luck with the "parallel to the ground" test.