250 Monza: leaking fuel tap is driving me nuts

[cooperplace]

This has probably been covered in other posts but I can't seem to find a solution. The LHS tap leaks. I took it off, cleaned the threads, used yellow (gas) teflon tape. Still leaks. Put in new fibre washers. Still leaks. I tried Loctite 567. Still leaks. I took the tap off, and used 250 grade wet-and-dry to carefully clean up the bottom surface of the tank (where it seals against the fibre washer) so it looks perfect -there was some crud there- and confirmed it has no cracks. Cleaned up the fibre washer. Put it back together using yellow teflon tape. Still leaks.

Petrol somehow gets past the fibre washer and forms a film that creeps up the outside of the tank.

I think it still has the original Italian taps.

This is driving me mad, and it's v time-consuming, draining the tank every time.

Someone suggested swapping taps to see if putting the LH tap on the RHS would shift the problem to that side, but I don't want to touch that tap: it doesn't leak!

Any advice would be much appreciated. In particular, is there an alternative to fibre washers?

thanks!

[Jordan]

Try a Stat-o-seal washer.
Buy a bolt or plug with the correct thread, to check for leak. Sometimes cracks are invisible.

[cooperplace]

well, I've just put a nitrile washer on and I can put my hand on my heart and say that no fuel is getting past it, but there's still a leak.

There seems to be some porosity in the paintwork on the part of the tank that the tap screws into. So yes, there's a crack or corrosion there.

The question is: should I take the tank to a tank repair place for welding? This will necessitate a new paint job. Or should I try an in-tank treatment like Kreem?

[graeme]

Hi Cooper,
I've had tanks with a hairline crack around the thread where the thread is welded (brazed) to the underside of the tank.
Cover the side of the tank in wet rags and re brazed the fitting to the tank.
(of course wash out and fill with water first)
Hirsch tank liner works if you want too do that, but if it's rust, eventually it'll bubble the paint anyway.
If it's rust you'll have to get it repaired properly so don't line it.
Oldani taps can weep are you sure it's not that? (New ones are cheap)

Graeme

ps, don't use POR15 tank liner, it's crap.

[cooperplace]

no, it's a definite tank leak, not the tap. Yes, I've heard that POR15 is not good.

[Nick]

KREEM it. I Kreemed my Diana tank about 15 years ago, rode the bike regularly for a year, parked it for ten years, and am now riding it again — no problems.

Just don't let even a single drop get on your paint.....