Noticed small rust patches inside fuel tank.

[borgy95]

Amazingly in the space of a week I have noticed rust appear inside my tank. I took it off Monday and today when I looked back in it I have noticed some small rust patches.

Can I still go ahead and drive around or must I attend to this immediately.

I'm not to keen on wrecking my engine.

I'm just amazed at how quick the stuff came up!

What's the remedy - tank cleaner?

[Weebl]

I have just had exactly the same with mine mate, although my bike was sat for a few years so it was more than just a few little patches!

As you probably know, the GPZ500s does not have a fuel filter as standard other than the screen filters attached to the petcock inside the tank. I can say with confidence, you won't knacker the engine, for the simple reason that the carbs will clog up with rust and the bike will stop running when rust flakes off and starts going down the fuel feed line.

I am not sure why yours has started to rust if it is full of fuel though? (or has fuel in it anyway) Perhaps you have a load of water in there too?

To clean it all out, the cheap and effective thing to do is drain the fuel out (put a bit, maybe half a litre in a clear plastic container and leave it for a day or so, water will settle out to the bottom and you will be able to see it) take the tank off and put some water and some stones in. Shake the buggery out of it, change the water often. when all the rust has been knocked off by the stones, you then empty all the water and stones out and leave the tank to dry (it needs to be immaculately dry, I left mine overnight in a warm room and also periodically used a commercial quality hair dryer down the filler neck) You also need to take the petcock off and apart to make sure it is clean. Might be a handy time to have the carbs off and see if the float bowls are full of crap too?

Top tips for filling with stones and swirling, use small sharp stones. Preferably make sure they will go in (and therefore out) the petcock hole, as if not they are a bitch to get out of the filler hole, you will have to bounce it around until you get lucky. You need to refit the filler and petcock for some of the time to make sure you are swirling all the way round the top, bottom and sides of the tank.

Once it is nice and clean, always keep some petrol in it to stop it happening again.

I also fitted a little inline filter in. It goes in the fuel in fitting on the carbs and is from a different Kawasaki but fits a treat with a little gentle persuasion. Part number 49019-1085 Less then a fiver.

Having just done all this, only in the last few days, if you need anything else or if my explanation is a bit flakey, just ask

[Weebl]

Just re-read your post, if all you mean is little bits of surface rust, and not flakey patches then probably the best thing to do is just make sure you have no water in your fuel, and then just make sure it always has fuel in. That will stop it rusting any further. So you can ignore my post above if it is just surface discolouration

[borgy95]

Brill cheers for the detail. It hasn't had fuel in it for the last 6days and had the filler cap and petcock out so bone dry hence the rust spots.

Its not too bad, it is surface rust/ discolouration. There is fuel in it now! I may have to risk it for the week. And next week I'll have the tank off and do the shaky shaky. Bit stuck on this as I need to be riding tomorrow. And the new paint is dry but still soft so I don't fancy moving it about to much today... Catch 22 really!

But anyhow thanks again at least I know how to fix it now

[Weebl]

If it is just discolouration mate, I would not bother. You only need to worry if it is scaling off

[eastanglianbiker]

if you are that worried get a inline filter and cut it into the fuel line between tap and carbs

[Roadtorque]

Most tanks are not treated inside, just bare metal, so what you see is normal & no problem