B11 fuel tank

Alas and alack, I am rapidly going off the plastic fuel tank on the Breva 1100, having done all the necessary in replacing the filter with an alloy one and opening out the breather and drain nipples, I now have a problem with water accumulation and what I will call “Spotty Muldoon” syndrome. After 2 weeks of non use, during which the bike was parked on main stand with a thick blanket over tank and seat and a hefty “waterproof” bike cover over that, the tank was found to contain approx. 1/2 litre of water and the paint had broken out in a rash of bubbles under the paint, almost all over. I checked the tank filler which seems to seal OK and the drain is clear. Where the hell has this water come from and what is lifting the paint? Any advice or an offer of a cheapish replacement tank gratefully received.Cheers, Gerry.

Water vapour from the atmosphere condensing within the tank would be my first guess. What is lifting the paint is a mystery to me too!

Half a litre? From condensation?

Plastic, or even painted surfaces are best not covered directly. Always try to leave an air gap for air to circulate. A blanket just holds moisture.The bubbles sound just like GRP pox.

Oo $#1T http://www.smithandcompany.org/GRP/GRP.html

Second hand tanks come up on ebay and some breakers have them in stock. My tank suffers from the same drain problems. I forced needles up the drain hole but it seems to do some tight turn inside so Im nervous of drilling the visible bottom hole . A drain test shows water draining slowly so ingress to the petrol is possible in heavy rain Mines kept in a lean to and im fair weather rider. So I guess more norge’s/breva should suffer if the bikes get as wet as yours. Maybe you need to double up on the waterproof cover and watch for pooling on the cover on top of the tank

there’s a black tank £249 on ebay search Motoguzzi 1200 sport tank. It’s with seller promotorcyclesalvage1


Thanks for all the replies, btw the blanket under the cover was dry. The osmosis suggestion sounds most likely for the bubbles, have had several locals complaining that they are getting hiccuping from car and bike engines which has been blamed on water in the fuel from filling stations, one local filling station has been shutting down regularly to drain water from storage tanks, due to very high water table levels the usual auto drainers cannot work. Guess a replacement tank is needed.Cheers, Gerry.

Depend on how much work you want to put in to the exiting tank.I had a GRP boat back in the 80s which suffered from this a bit, quite common back then, but I thought they had got the mixing techniques improved these days.Back then you removed the blisters which contain styrene, let it dry out, then fill with epoxy, smooth and repaint. Of course finish is not so important when it’s under the waterline.

Brian, most of the bike has been under the waterline in the last year Seriously, will have to get a replacement tank even if only so I can ride while fixing the original, have subsequently found some blisters on the inner liner also so a reline is in order, Caswell from the states is recommended, also sold in UK (Borden, Hants). Pete at Reboot apparently has a tank, just awaiting reply.Cheers, Gerry.

I find phoning Pete is best…Have to say that is one wierd problem never ever seen it on a Bike fuel tank and my first big bike was a Norton Commando Fastback with plastic tank.

I wonder if once you swap out the oem tank if you could find a steel tank that is similar and use the old tank to get the bottom tunnel reshaped.

A local custom bike shop should be able to do that or am I being too simplistic?

Hi GB, you have obviously not seen a later Guzzi tank in it’s naked wonder, I think the term for the shape is “organic”, plus the back end contains the fuel pump and filter. To fabricate a replacement metal tank would be the work of a sculptor in steel or alloy.Cheers, Gerry.

Oh dear no I have’nt and to be honest I have to wonder why manufacturers do that. mind you there will be a way around it. … I wonder if you could fit an external fuel pump/filter as per the V11 Le mans… But haveing never seen the underside of the Breva I have no idea…

Replacement tank on its way, having thoughts about doing a “cutaway” section on the old tank to show owners how it is set up, anyone got a dead pump/filter unit that I could incorporate? Band saw at the ready. Might make a good display on a stand at bike shows, etcG.

New tank fitted, good as gold, many thanks for all the helpful hints. Did the boring out of drain and breather nipples with a 2mm drill then blew out with air, small (dead) bee emerged! Surprisingly a grey tank looks quite good on the black bike with black seat. Still looking for a dead pump/filter unit, especially with the bulging original filter, to set up a cutaway display. Any offers?Cheers, Gerry.

Bluddy insects

Good News gerry, well the V11 Le mans has black tank bag thing and it actually looks far better with the red/grey than the Baglux Grey one does. Oh I found on e-bay some silver decal eagles they go onto the black tank bag a treat.

Gerry I have got a bulging original filter if you want it!!

Thanks, Wits, let me know how much to post to
(address removed ) .
Or I can make a donation to the Air Ambulance.
Cheers, Gerry.wits2013-03-07 22:23:44