KZ 650 tank leaking behind badge - options?

1979 KZ650 - The paint behind one of the badges was bubbling pretty bad so I took the badge off and started picking at the paint and sure enough it was rust, so I start flaking off some of the rust and gas started leaking out from behind the mounting "plate" for the badge so I took the tank off and drained it. I'm painting and debadging the tank anyways so can I remove the badge plate and just fill it after the hole is repaired and sealed or is that plate welded in there?

I'm also looking at just buying another tank. I still have to dig into the current tank and remove the rust to see if any other leaks exist and deep the rust is. But if it gets worse another tank might be a better option. This site has several tanks for KZ650's but no year so my next questions is what 650 years and models are interchangable? And they have a few listed as CSR that look different from mine.

www.cycleramasales.com/site/1538094/page/642659

What model '79 do you have? I just saw your pics, you have a B model.

B and C models from '76 to '80 are the same tank.
D (SR) models from '78 to '81 are the same.
F series from '80 to '83 may be the same as the B and C models as well.

Check out this site for the different 650 models: 650s

Post edited by: rstnick, at: 2006/03/23 14:13

1978-1979 KZ650B and C is a direct replacement for your tank, but 1979 had different badges. 1980 really wasn't a model offerered in the USA at least. 1977 tank will also work, but your fuel petcock will not fit unless the outlet hole is enlarged on the tank. 1976 really wasn't a model of KZ650 although some were possibly titled as 1976 because they were built in 1976. For all intensive purposes, the KZ650B and C was a 1977-1979 model run.

What I've used on tanks that you can't seal using Kreem or Por15 is an marine epoxy resin to line the tank.

West systems marine resin epoxy. 105 resin and
205 hardener

This mix creates a hard shell inside the tank that's impervious to gasoline. Use a 5:1 mix.

Hey puckaveli. If you are interested I have a really nice spare Kz 650 tank with petcock, gas cap and key I will part with if you are interested. Check your messages I sent you a u2u.
Cheers-Colin Firth

if not , can i buy the cap & key?

Thanks for the help I went to a local salvage yard and they had a good selection of KZ tanks, so I got a nice 650b tank for $100. www.cycletherapy.com is the place in case you need something.

You can't fix rust. If the entire area is rust, you need new metal and will have to cut and weld or at least cut and braze. If the area is small and you can grind off the welded-on badge bracket, you can use JB Weld. That will fix the gas leak permanantly. Since the rust occured from the welded-on bracket, hopefully the tank rusted from out to in rather than vice-versa.

I fixed a badge leak in the 80's by brazing in new metal it can be silver soldered too. I don't know if this is still valid because cars now have catolitic converters and i m no sure if this makes a difference. I rode the bike to my buddy's shop we emptied the tank of gas and stuck the fuel filler hole over the exhaust of his car and left it on tick-over for 20 minutes. The carbon monoxide killed the gas fumes and we able to braze on the tank. Let it cool down put it back on the bike and rode home.

Thanks for the post. I hope you are not planning on a big conversation here. Nobody has posted to this thread in more than 11 years. Many of the participants have moved on.

TexasKZ wrote: Thanks for the post. I hope you are not planning on a big conversation here. Nobody has posted to this thread in more than 11 years. Many of the participants have moved on.

Good news is he used the SEARCH function to find info!

This is a topic I reference occasionally when someone has a fuel tank in poor condition & wants to line it. particularly the reply by Jeff.Saunders.

tag = west systems marine epoxy.