Katana Owners Club U.K.

She wouldn't start the other day, pilot jets blocked. I found small particles of rust in the float bowls and in the tank. The tank is very clean except, from what I can see, a small rust patch. I've cleaned the tank out and filtered the fuel and she running fine now. This won't be a unique fault on these historic old bikes, any advice on the best tank treatment? Flowliner treatment read very well.

If it's just a patch of rust try using EVAPORUST it doesn't harm the metal, I had a small rust patch directly below the filler cap after the tank came back from a respray and the sprayer hadn't masked it off properly, didn't want to line the tank (especially as ethanol seems to dissove everything) popped the evaporust in the tank for 24 hours and the rust patch had completely gone, best thing is you can use it again and again (or lend it to someone) and when it eventually expires you can pour it down the drain, another good idea is to fit an in line fuel filter with a small neodymium magnet gaffa taped to it, the magnet hoovers up any rust particles that try to get through.

If you wish to line the tank
https://www.ebay.co.uk/itm/303125888490 ... eeUTEvInn6
Is one of the only ones that is Ethanol usable.
If it's just a small patch as said in line filter and a magnet near the tap on underside of tank works very well.

Thanks guys appreciate it, some handy ideas there.

If the tank hasn't got holes in and isn't too bad I would just de-rust it. I would say a liner is a last resort.

I have paid for rust remover but watch this video - https://www.youtube.com/watch?v=fVYZmeReKKY, the guy does guns and compares his own formula (which he gives you) to Evaporust very thoroughly indeed, even weighing test pieces to compare metal loss, it really is worth watching and you'll never buy de-rusting solution again and this is so cheap to make! I used his formula on some of my 250 parts, see images.
You might have to give it a little hand with a wire brush every now and then if quite rusty, but I thought it worked really well. I did these before painting and also some other parts, like nuts and bolts before zinc plating (also fairly easy if you are happy with a duller finish then the bright zinc which an industrial plater would do).

If you really want to use a liner then I have used the kit from here https://www.tankcareproducts.co.uk/ on a Yamaha GT80 that had a failed liner in it. I spilt some on the drive (tarmac) in 2020 and it's still there.

UB

Hi, Rob, sent you a private message in reply to your request from July for 250 Kat photos, sorry it's so late but I forget to check the PM's

I would agree with uncle Bob here, if it doesn't have any holes, just derust it.
I use Scalex, it's basically industrial phosphoric acid, and converts the rust to an inert material which can be brushed off or painted over.
Inside the tank you can either brush it on if you can reach the spot, or for a bad rust situation, put a pint in and swirl it around. Don't leave it in for too long though, unattended it will eat through the steel eventually. (I left some bits with circlips on in it over night....circlips completely disappeared!!

Went with POR15 spent all day yesterday on it, time consuming and all too easily becomes a tad messy when draining the tank from excess sealant!!
Appears to have coated the tank very well indeed, looks like new.
Now its standing for a minimum of 96 hrs.
Thanks for all the advice guys.