Author Topic: Fuel Tank Cleaning  (Read 264 times)

Offline Spenny62

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Fuel Tank Cleaning
« on: March 14, 2019, 02:01:21 PM »
I'm having a few problems with dirty fuel and think the tank has rusted inside with standing (there's no sign of the tank having perished).  It has had a good clean out with caustic soda and well rinsed after but it seems that there's still rust inside which is getting into the carbs and now clogging up the inline filter I've fitted.

I've already had the tank sprayed so don't really want to buy a replacement. 

What are my alternatives?

Offline Nurse Julie

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Re: Fuel Tank Cleaning
« Reply #1 on: March 14, 2019, 02:12:01 PM »
If it's a 400/4 tank, its got a big long filter in the tank attached to the petcock. Maybe the caustic soda had destroyed this filter, so any crud would be going straight in to the inline filter you have fitted. Another option is to fill the tank with pea gravel and soapy water, or similar, and shake like hell to help remove more of the rust.
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Offline Sprocket

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Re: Fuel Tank Cleaning
« Reply #2 on: March 14, 2019, 02:30:39 PM »
empty tank. Really very empty.  insert pea gravel as above^^. wrap in duvet. insert package to tumble dryer. 20 mins on the ambient setting (*no heat!) and you're clean.

Offline PatM

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Re: Fuel Tank Cleaning
« Reply #3 on: March 14, 2019, 03:18:03 PM »
Ive had various tanks with that problem- bits in fuel.

I had a brace of Mobylettes a while back and used CITRIC ACID and sealer.(Moby's have integral frame and tank, so wont fit in a tumble-dryer!!)
My present tank has a sealer applied- which has come away in lumps- looks like bits of gel-coat.
Anyway, ive cleaned out what I can and fitted an inline fuel-filer- its been like that for about 5 years now with no further issues except a leaking inline filter- which i replaced.

Online kevski

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Re: Fuel Tank Cleaning
« Reply #4 on: March 14, 2019, 04:20:38 PM »
Caustic is the wrong thing to clean a tank out with, ideally you should pickle it with a solution of 10/15% sulphuric acid and a piece of stainless chain mail, seal it up shake around for a good half an hour,empty and wash through with lots of D.I water, dry quickly and apply some WD40, then make sure you have the internal filter in the tank and preferably an inline filter too.

Offline PatM

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Re: Fuel Tank Cleaning
« Reply #5 on: March 14, 2019, 06:30:55 PM »
My petcock after many years...

Offline mattsz

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Re: Fuel Tank Cleaning
« Reply #6 on: March 14, 2019, 07:38:28 PM »
Filter looks like it's working!

Offline Rob62

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Re: Fuel Tank Cleaning
« Reply #7 on: March 14, 2019, 08:42:33 PM »
I have used the electrolyte method in the past with great success... remove petcock, seal the remaining hole, fill with electrolyte to the brim, suspend a metal coathanger or similar in the filling hole isolated from the tank with a plastic cap (make a hole in the cap and push the top of the hanger through it) this will be the sacrificial anode. Connect the positive lead of a battery charger to the part of the anode poking out of the top of the cap and the negative to the tank itself (a bared area of metal on the tank). Keep an eye on it at first to make sure it isnt shorting, it should be ok with just a bit of fizzing.... leave it for a few hours, you may use up a couple of anodes... the rust will migrate from the tank to the anodes... keep going till the rust has gone It works! You will be amazed at the amount of crap that builds up on the anode... Lots of detailed advice on the internet.

Online kevski

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Re: Fuel Tank Cleaning
« Reply #8 on: March 15, 2019, 07:02:06 AM »
The tank has to be the sacrificial anode, otherwise you are plating the rubbish to the tank.
« Last Edit: Today at 08:40:26 AM by kevski »

Offline Athame57

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Re: Fuel Tank Cleaning
« Reply #9 on: March 15, 2019, 09:56:23 AM »
I gave up because it simply went rusty again. I got a new tank and fittings from David Silvers. I had trouble fitting it at first and they tried it out for themselves and found out that it was a bit narrower at the fitting arches. I and anyone else had to reduce the size of the mounting rubbers so it would slide on.
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Offline Northy

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Re: Fuel Tank Cleaning
« Reply #10 on: March 22, 2019, 10:04:42 PM »
Spirit of Salts or brick acid , I use SOS  cleans it so well  you need to add in caustic soda to neutralise the acid or it gets covered in surface rust instantly . Once the caustic is out then rinse with water , add in petrol/ oil mix.  Best bit its quick , couple of hours tops and cheap £3  for  500ml is more than enough  for one tank. 
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Online kevski

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Re: Fuel Tank Cleaning
« Reply #11 on: Today at 08:45:18 AM »
Spirit of Salts or brick acid , I use SOS  cleans it so well  you need to add in caustic soda to neutralise the acid or it gets covered in surface rust instantly . Once the caustic is out then rinse with water , add in petrol/ oil mix.  Best bit its quick , couple of hours tops and cheap £3  for  500ml is more than enough  for one tank.

By applying caustic to the acids you make it harder to rinse out quickly, D.I water is whats needed and plenty of it, if we had added caustic at this stage of the process on our plating line we would have so much contamination we would of failed every time.