Whining fuel pump?

[greywolf]

And don't remove bolts with a torque wrench. Use it only when installing bolts or you can damage the tool if a bolt is stuck.

[pr]

Yes, I wanted one for the installation. I saw it needs 10 Nm.

First look at the tank reveals a bowl of bran flakes... When the fumes have cleared I might dismantle the pump assembly and see how that looks.
I didn't buy the POR15 in the end. I saw a second hand tank on ebay that looked in good condition. I might fork out the extra pounds and save myself a dirty job.
Why aren't these tanks made of stainless steel?

[greywolf]

Stainless steel is difficult, read expensive, to curve form and seam weld. It's a painted piece and only gets corrosion inside if it is mistreated. Keep the tank filled with stabilised fuel if it isn't being used for weeks at a time. If it isn't going to be used for over a year, drain the tank and oil fog the inside. Some people like to coat the inside with a permanent coating but that fell somewhat out of favour with ethanol in fuels that liked to eat the coating.

It's leaving an empty or partially empty tank in cold weather that causes problems with moisture in the air in the tank condensing on the metal walls and causing rust. Don't do that and it's likely never to be a problem.

[Fat Rat]

The inside of that tank looked nothing like that when it was here Paul  I can only imagine that the damage was done (as Greywolf says) when it was sat idle. It seems to me that now you have started putting mileage on the bike the bran flakes have dislodged from the inside of the tank presenting you with this problem 

Is a secondhand tank the answer (you could be buying the same problem)? There must be companies who will clean and treat the inside of your tank?

Also, I'd be interested in seeing the inside of the Pump assembly (bottom gauze filter)

[greywolf]

The picture clearly shows all the corrosion occurring at the top of the tank in the air space above the fuel.

[Barbel Mick]

I sent a pretty knackered tank (somebody had tried to repair it with sealer themselves and failed miserably!) off a Kawasaki Zephyr I had to these people... http://www.fueltanks.co.uk/service/motor-cycles/
They did a great job of the repair and respray but it wasn't cheap!!!! Can't remember exactly now, it was a few years back, but it was well over £200 then!
Maybe give  'em a call and ask about the GTS 1750 gas tank sealer?

[pr]

I tried my best to keep the fuel level as full as possible at all times. I use the bike about once per week, but sometimes it stands still for 3 weeks when I'm away. Sometimes a bit more, but usually for a trip of about two or three hours. I try to top off the fuel before putting it back. I also let it cool down before I put the cover over it (to prevent condensation).
Any specific kind of fuel stabiliser you would recommend?

Thanks for the tip Mick. But I'm still considering the tank replacement. On the pictures it looked in good condition, and I can have it fixed sooner for about the same price. The dealer quoted a similar price for a rust removal.

I might have a look at the pump assembly this weekend.

[Barbel Mick]

Just a thought, if you go for the replacement tank have a go at cleaning the old one. I had a go at mine but couldn't get the old sealer out, it was set solid in lumps at the bottom presumably because whoever tried to repair it didn't rotate the tank enough to get an even coat on the inside. You haven't got that problem though, just rust.
I threaded a few dozen nuts onto a chain and put it in the tank with the filler and pump holes blocked and shook the hell out of it, for as long as I could, every day for a week or so. On advice I did leave the tank to 'breathe' for a few days before that just in case a spark ignited any fumes left in the tank!!! Then you could try the sealer kit. If it works you've got a spare tank or sell it and get your money back?

[pr]

Good point Mick, I will try at some point. It's still breathing in the shed outside.

When putting the tank back together, I should replace the big O-ring between pump and tank. Is that really necessary? If yes, I need 99000-25010: Suzuki SUPER GREASE “A”. Is there an easier to get, and probably cheaper, version of that stuff?

Same for the small O-rings in the pump assembly: should I replace them whenever I want to have a quick look inside?

[pr]

PS: with big O-ring I mean nr. 14 and with the small ones I mean 5, 6 and 7.

http://imgur.com/a/ORGpH

And another question: while the bike is now partially opened up (fairing+tank off), what would be things to check and grease?

[Fat Rat]

5,6 & 7 were replaced by me Paul, I'd save your cash.

[Fat Rat]

Have you split the assembly yet? I'm keen to see the filter at the bottom (item 2 on the diagram).

[pr]

No, I'll plan to do that this weekend. Best case scenario is that the flakes were blocking the flow towards the strainer, so it's still in good shape. The the hp filter could also be good then. I'll post it when I know it.

I'll replace the big o-ring then.

[pr]

The Suzuki super grease, what can I use as a replacement? Vaseline? It's to seal the o-ring

[greywolf]

The grease is just to lubricate the O-ring so it finds its proper place and doesn't catch or bunch up and deform. Since Suzuki's grease is petroleum based, the O-ring material must be a synthetic that is okay with petroleum products, so Vaseline will work.

[pr]

I replaced the tank and fuel pump. The second hand tank looks really good: shiny on the inside. The second hand pump, I;m not yet sure how it works. It is a bit loud when the bike idles and when it primes, so I'm not convinced it's a great improvement. Before taking it for a test ride, I'll take the old pump apart. 

I removed the 3 screws of the fuel gage floater and took it off. Now I need to pull the pump assembly out. Do I need to pull really hard? Or did I forget a screw? The K9 service manual I found on this site is actually the pre-K7 pump assembly, so I can't check. It looks similar to the Glee manual though

[pr]

I mean removing the fuel pressure regulator holder. I just have to pull it off? It's quite stuck.
After looking a bit harder in the manual I found K7 fuel pump spec on page 550 

Shaking the pump assembly seems to give a big shower of rusty flakes 

[pr]

Really tight fit, that was, but it's apart.

It doesn't look too bad on the inside. All the big stuff is now out of the housing and it's mainly rust and no other crud. The strainer has some rusty dust, although I;m not sure why it has a greyish glow (used to be white). The main problem might have been from the huge amount of flakes that was blocking the flow.
I think I will clean it, put it back together and see if I need to install this pump again.

[pr]

I took it for a ride with the 'new' pump. Pump was still a bit noisier than I expected, but it performed really well and the whine is lower than the old one. No problems getting to 9-10k rpm.
So I'm calling it solved. If I keep the tank clean then the filters should stay nice and clean. I'll give the old unit a good clean in the future and keep it as a spare or sell it with the tank.
Thanks all for your input!