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utopia
12-09-2011, 03:29 PM
Not Ducati related, but .....
My mate has an RD350LC that he's owned for 25yrs. It doesn't get much use. It gets a new mot each year but then spends most of its time parked up. He's not really a biker. I don't think he's ever taken it beyond the county boundary.
He does virtually no maintenance on it, other than what is strictly neccessary to get it through the annual mot test each spring, and he has always scorned my suggestion that he should drain the old fuel before its annual re-emergence. He doesn't even charge the battery up after the winter layoff, and has always delighted in the fact that it starts up without much problem despite the neglect.
This year, it was the same story, but it didn't run too well, and eventually it refused to do much more than tick over in a lumpy fashion.
The inlet manifold rubbers are badly perished and cracked, so it was decided to do a full overhaul of the fuel system while changing them. Starting at the beginning, he decided to drain the fuel tank.
All went well at first, with reasonably clean fuel coming out and being transferred to his ratty Astra. Things were not so good at the bottom of the tank though, and we eventually drained out.......... a full LITRE of water !!!!!
That seems like an awful lot of condensation, though it could have accumulated over 35yrs, so I guess that would only be half a dozen teaspoons or so per year. Still sounds a lot though, and the filler neck is raised so it doesn't look like it can have leaked through there.
It runs a treat now, even with the perished inlet rubbers, which I suspect will now remain in place for a few more years.

And before anyone asks.....no, he doesn't want to sell it.

gary tompkins
12-09-2011, 05:00 PM
The tank may start to leak due to rust

The water will have been laying at the bottom - it's why a lot of monster tanks fail around the hinge

Albie
12-09-2011, 05:00 PM
I know I asked the other week :chuckle::chuckle::chuckle:

Twentytoo
12-09-2011, 06:02 PM
I had to drain the tank on my 06 zx6 when I realised water easily found its way in when washed

Gareth
20-09-2011, 07:01 PM
Water plus air = rust, so in theory a tank full of water doesn't always mean a tank ful of rust....but from experience its what you usually get. Fuel filter a good idea if there isn't one aleady, saves clogged up carbs.

digga
20-09-2011, 07:39 PM
never mind the water ...

its bloody criminal to treat a `classic' in such a way - ho ought to be ashamed of himself !!


drain the tank every year ... the fuel is next to useless, just sitting there losing it power.... even i drain the lawnmower every year :(

Albie
20-09-2011, 07:47 PM
Further to this post I now find myself in a dilemma. The Yamaha srx tank is an antrociuos design .
I have just read a post saying that most of the tanks go rusty due to water. This is caused by the fact that the fuel tap is over 4" higher than the lower level.
So this means that the fuel must go off down low presuming it turns to water and rust. After reading this yesterday morning I went into the garage to see as I had not yet remove the tank.
Guess what !! the bottom edge is thick with rust. Thankfully it has not broken through yet but at least I have time too sort something out.
I have considered looking at a different tank so will be browsing take shapes that would look ok. Maybe even a monster tank.
Why wouldn't you put the tap low down :dunce::dunce:

utopia
20-09-2011, 09:04 PM
Its not just yamaha.... the tank on my honda dominator rusted through on both sides at the low point. It was only about 10yrs old at the time. It seems that they don't make 'em like they used to (the tank on the RD seems fine after 30yrs).
I did a rough and ready repair on the dommie tank by cutting out the damaged area and soldering on a thin copper patch. It probably won't last too long like that, but its been ok for a couple of years.
The RD sees such little use that last year it was parked outside the front gate for so long that a passion flower scrambled all over it. We thought it was quite a nice image, so it ended up featuring on the cd that we recorded that year. I'll see if I can dig out a copy to post up.
Aluminium alloy is the only proper material for a motorcycle fuel tank, in my opinion.

the_adam
22-09-2011, 01:37 PM
Can anyone give me the symptoms of a small amount of water in the tank? Just read this and wondering if my problems might fit :idea: Basically, the bike is idling progressively lower so I now have to leave the choke on permanently, it also feels like it has lost power and is generally very lumpy at lower speeds (I know they aren't great for this, but it used to be better!)...it's always hard to tell but I think the mileage I can do on a tank has come down slightly too. It also just feels like a better bike when leaving a petrol station with a full tank, that's what got me thinking...

My last bike was a Sachs XTC - well known for having a fuel cap like a sieve, it wasn't a good idea to use it in the rain without a tankbag. But that would either run or get enough water in it to cut out completely, I've never had it happen progressively before. I know that if I just took it to a mechanic whatever problem could probably be sorted out, but they have a habit of charging for it! :worried:

He11cat
08-11-2011, 02:07 PM
I don't know about your bike but some of the M600 's inc my old tank I would notice a bit of water gathering around the dip in the fuel tank hole.
Blocked drainage hole and some seem to let a bit of water in under the cap bit.
Have you checked your drainage hole?
I have a different tank now but i would when not using leave a bit of kitchen roll in the dip just so if anything leaked in that would soak it up rather then getting in the tank. Also I could monitor it Now the tanks off a clean out of the hole will sort it out. Only reason I didn't was because I knew I was changing tank shortly. Think its a common problem but this was mainly when the bikes standing rather then travelling.

I would take out the kitchen roll before I went anywhere and was careful not to knock it into the tank.
Bit bodge it but just that I knew if water was a problem or not.

I spose the only way would be to try that and if the case I guess run your tank down and drain it and fresh fuel.. however.
Wonder if its something else if progressive.
See if you are getting water in round that rim.

adey
30-08-2016, 01:08 PM
hi all

i am having a similar problem to the one adam reported in 2009.

i now have '06 S2R (in case my profile details are out of date). it is acting similarly to how adam's was - idling lower and needing more choke, and most noticeably, running very lumpy at constant speed (is ok under power). this seemed to start after an epic downpour earlier in the year in which it was standing all day. i took it to metropolis in vauxhall and they eventually found water in the tank and drained it, explaining that the overflow pipe could get blocked and water would backfill and flow into the tank under the cap.

i think it improved but the problem has recently reappeared so i took it to david robinson in wandsworth today. he suggested that the water in the tank could be the issue but that it could potentially be other things, which he will investigate. my money is on the water.

it seems a pretty ****ty design flaw if rainwater can get in the tank. i may try he11cat's suggestion of kitchen roll under the cap while standing, but wondered if anyone else had experienced this and, if so, if they had any suggestions (other than a tank cover / keeping it out of the rain)?

i haven't yet noticed if the issue is less pronounced with a full tank of petrol, which i suppose would suggest that water is the issue, but will check.

thanks for any advice / suggestions all.

adey

Darren69
30-08-2016, 02:08 PM
Most pump fuel will have varying amounts of water in, which if allowed to stand will settle in the bottom of your tank over time so even if your tank doesn't let water in you are still putting some in each time you fill up.

Darren69
30-08-2016, 02:13 PM
And further add to the problem the ethanol they add to fuel now is hygroscopic so it will attract water from the atmosphere which will also end up at the bottom of your tank.

Mr Gazza
30-08-2016, 02:16 PM
metropolis in vauxhall and they eventually found water in the tank and drained it, explaining that the overflow pipe could get blocked and water would backfill and flow into the tank under the cap.

...So did they clear the overflow?

It would be a good idea to check the whole run of pipe from the bottom to the filler yourself.

I don't get how kitchen roll under the cap would work, as it will just soak up any water before it can go down the hole.. Blocked or clear.

Personally I would start by changing the spark plugs.

Kato
30-08-2016, 02:16 PM
This will almost certainly get worse for everybody with the increasing amount of Ethanol in fuel, as Ethanol attracts water like a sponge

emzedder
30-08-2016, 08:16 PM
Yep, that's likely Ethanol .... attracts water that separates and sinks to the bottom causing rot and is the bain of vintage bikes. The only way is complete drain before standing and coat inside of tank with slosh of twostroke oil ... Ethanol completely dissolved one of my tanks no question about it

DrD
18-10-2016, 10:46 PM
Re ethanol most forums circulate what Triumph TR register said in 2013: http://www.groups.tr-register.co.uk/wessex/ethanol-update.html
I think it has now changed with BP, Total and Esso premium being the only ones for definite (outside of Devon and Cornwall)
Total are helpful with their E0 garage register (from MGB forum): http://www.mgb-stuff.org.uk/total_e0.pdf

The classic car forums are a really good source of info regarding E0 sources.