Tank restoration advice KZ1000A/ KZ900

My 78 KZ1000A had a LTD tank fitted at some stage, I wanted the original tank and dropped on a KZ900A tank on a good deal which is near enough to the original for me. It fits the bike perfectly, but needs painting. The swap has brought up some questions, some anticipated, some not.

1) Firstly paint. It will be painted black to match the existing bodywork. Is it better to strip all the old paint back to bare metal, or just sand it down and paint?.

2) The inside of the tank is really nice, it may have been cleaned for rust at some point in the past, but it's not pitted or any thing, no sign it was rusted. It does have a bit of a rust mark, more like a stain immediately opposite the filler cap. Should I leave well alone, try something like vinegar or go for Phosphoric acid if this will protect the interior down the road?.

3) Tank emblems: This is where I'm confused. I've heard of the two sizes 122 mm? and 140 mm spacing. My existing limited tank has 122 mm screw spacing and so does my replacement KZ900 tank. The stuff I read said the Z1's were the only ones with this spacing, the KZ900 would be 140 mm as were the KZ1000's. Obviously that doesn't compute, given my two tanks. I'm wondering if the 900 tanks had 122 mm spacing as well as the Z1's and my exisitng "bastard" tank is a 900 LTD tank. Any clarification appreciated, although as it stands it's a plus the emblems from my existing tank, will fit the new one.

4) Gas cap: This appears to be held on by a roll pin at the rear pivot. Do you just knock that out with a small punch? and is it reusable? Any tips for removal like knocking pin out with it locked closed to avoid it falling on the tank or similar?

5) Does anyone know if the dimensions and shape are similar enough to a Z1 tank, that a Z1 decal kit could be used?

Thanks in advance for your assistance. I've attached a picture of the existing tank on the bike and the KZ900 tank.








It looks a lot worse in this picture than in the flesh, but to give an idea. A lot of the dark is just shadow, there is the surface rust in the center.

I have a Z1 and a KZ 900 tank. They are interchangeable. You tap out the roll pin with a small punch. Getting past the pin stripes will be the hardest part. You can use a heat gun to get them off. You will notice the paint underneath is pristine. I went solid color 35 years ago.No more pin stripes. I'd sand it and paint it.
Steve

1) Strip the old paint with paint stripper. Get the good stuff, the type that washes off with mineral spirits, not water.

2) I'd do a phosphoric acid treatment. When rinsing you gotta be fast with some alcohol or WD-40 after rinsing or you can get some flash rusting though.

Not sure about the rest...

I'd strip back to bare metal, there are other ways of doing this - just the way I do it. Also I'd remove the fuel level gubbins and shake a dog lead chain (with string to extract) through it to remove any loose rust. I've used tank sealants and phosporic acid rinse but I'm unsure about it now particularly if you think it is sound inside.

When painting, leave the lip of the fuel filler bare like in the factory, also the fuel tap area...the petrol gets under the paint and can cause peeling.

Those OEM stripes are a pain, you have to get them completely off. Nice tank to paint. no dents or body filler on it.
You need to buy a set of crappy chrome fenders and paint them black too! My style!

Nice tank to paint. no dents or body filler on it.

that's what i was thinking, assuming there is no nasty suprises underneath it...hence the bare metal process.

Getting good metal and plastics to paint is half the job done, restoring crash damaged bodyparts is a fools errand if it can be avoided. Been there,done it.

When you reassemble the fuel cap, put multiple layers of painters type masking tape over your new paint job first all around the filler neck and top of the tank.

Kidkawie wrote: When you reassemble the fuel cap, put multiple layers of painters type masking tape over your new paint job first all around the filler neck and top of the tank.

I thought about doing something like that, because I guarantee the chances of something dropping on the new tank paint are about 100% with my luck.

Intstalling the roll pin.

just don't paint the filler cap lip - over time fuel vapours work under the paint and it will peel. Been there, done it.

Thanks on that tip, they always seem to paint that piece and it also usually looks a mess too.

Kidkawie wrote: Intstalling the roll pin.

Might not even get that far before dropping something on it - perhaps I should wrap the whole thing in bubble wrap or bullet proof vest material.