Early metal petrol tank - carb

[Big Daft Lad]

I know I'm looking for the impossible but does anyone have a decent tank that isn't rusted through and doesn't have any dents in it?

Actual paint condition or colour is irrelevant as it'll be getting painted. It's for a 1996 M600 but I think the 750's and 900's were the same.

[Darren69]

I have noticed that these are getting hard to find now and they are getting very expensive too even for a dented one. You can use a metal injection tank if you fit an SS fuel pump but the seat wonl't fit as well around the tank as the shape changed, which is more hassle and expense and you have to change the seat latch to fit a later seat. There are a few more metal injection tanks around but again not cheap. Keep looking on ebay or maybe one will turn up on here? I suspect most with a spare will be hanging on to them but good luck.

[Darkness]

The early and later M600 seat bases are the same plastic moulding, though are trimmed differently at the front edge to make the sharp and rounded shapes where they meet the tank.
It is simple to swap over the keep for the seat lock by undoing one bolt and sliding the old one out. You don’t need to change the latch on the frame.

[Darren69]

That should give you some more options then and actually the later seats aren't that expensive, probably cheaper than a re-upholster job anyway. What is the issue with your tank? Rust? Dents? Leaks?

[Big Daft Lad]

It's leaking so presumably rusted through. Is been sitting in my garage for a decade (I know I'm bad man but life got in the way). It also has a dodgy paint job on it after I dented the tank.

I've been offered a plastic tank from a carbed bike but I'm undecided. There will be different connectors etc I'm sure. Are the plastic tanks affected by ethenol petrol?

[Darkness]

Yes, the plastic tanks tend to swell when water separates out from the ethanol petrol.
But at least they don’t rust and ethanol is still optional in most of the UK.

[Nasher]

I've been offered a plastic tank from a carbed bike

I didn't think there was such a thing, I thought plastic tanks were introduced after the adoption of injection.
But I'm probably wrong.

Nasher.

[Darren69]

I think the plastic tanks are all for injection bikes and have large circular hole for the fuel pump assembly to fit into. All the plastic ones ive seen are like that. Im not sute if you can put the ss fuel pump into the pump assembly on those. Maybe you can?

[Big Daft Lad]

Hmm, I think I'll stick to what should be on the bike. I'm not in a hurry I'll see what turns up.

Maybe I should put a liner put in and respray it.

[Darren69]

My advice is to get it cut and welded, tank sealant is really a bodge not a proper repair.

[utopia]

Depending on the general appearance of the innards of your tank, It might be worth pressure testing it to find out exactly where the leak is.
Steel tanks commonly spring a leak around the rear hinge attachment, caused by raising the tank while its carrying a lot of fuel. The lob-sided tank prop doesn't help matters as it imparts a twist on the hinge.
If that is the source of the leak (and the rest of the tank is reasonable) then its not too difficult to repair by brazing.
A search should reveal previous threads on this aspect .. I remember Big Oz repaired one or two in this manner a few years back.

Its also probably worth inspecting any replacement tank closely in the hinge area to ensure it hasn't suffered thus.

If I remember correctly, the earlier tanks are most easily identified by the presence of a seam around the front cutout area where the ignition lock sits.
Later tanks (after about 1999, I think) are smooth in that area.
As others have stated, early tanks also have a more pointy recess where the front projections of the seat fit.

[slob]

There are a few, very rare, Acerbis carby tanks out there.

[Big Daft Lad]

Thanks for the advice, I'll have a proper look at it and try to get some photos up for you to assess :-)