fuel tank issue

If it's broken or just needs tweaked

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ppennington
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fuel tank issue

Postby ppennington » Sat Feb 06, 2010 11:49 pm

I've got an 82 cb650 and the tank is pretty rusted out and i'm pretty sure i can't resurrect it. is it possible to swap out the tank with other cb650 styles? i dig the bike and REALLY want to get it up and running. any suggestions? thanks a million.

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Volker_P
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Re: fuel tank issue

Postby Volker_P » Sun Feb 07, 2010 5:03 am

Welcome here! :D
Sorry I can't help directly, I just know that custom tanks and Z-model tanks are not directly interchangeable (different length, but already seen that made fit). Moreover Honda did tricky things like e.g. changing the fuel cock thread size between years and also other parts that look similar often distinguish by some details. So the only advice I can give is have a close look on whatever you get for your CB.
Hopefully one of the US guys can help more precisely.
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pae
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Re: fuel tank issue

Postby pae » Sun Feb 07, 2010 5:52 am

Hi and welcome to the site.

I can't help on the tank either, but good to have you here - someone will have some ideas soon on tank alternatives.

cb650
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Re: fuel tank issue

Postby cb650 » Sun Feb 07, 2010 10:40 am

If you have a standard model any 81 will also work but you need to check your petcock. I dont know it the 82 petcock was held on by two bolts or screwed on with one big nut like the 81's. A 80 will fit but had a smaller petcock but can be used if you get the petcock with the tank. 79 and other z models wont even fit as they are a longer tank and mount diff.
A 82 nithawk tank will fit but is styled diff. Bill might have a nitehawk tank he will get rid of.
Did you clean the tank out?!?!?!?!

oregonandy
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Re: fuel tank issue

Postby oregonandy » Mon Mar 22, 2010 12:22 pm

While we're on the topic. . . my tank is "slightly" rusted. . . on the inside (with no gas in it), I can rub some rusty grit off (so that rag comes back orange/black from the rust). It doesn't seem THAT bad, but enough to make me wonder -- anyone know of a way to treat the tank to stop the rust?

-Andy

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Volker_P
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Re: fuel tank issue

Postby Volker_P » Tue Mar 23, 2010 3:46 am

Yes: fill in fuel. Especially fill full while standing over winter or for longer. If you don't trust your petcock, also disconnect the fuel line to the carbs.
But first, you have to get out the rust as good as possible.
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Jeremy
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Re: fuel tank issue

Postby Jeremy » Sat Mar 27, 2010 12:20 am

i just fixed this problem on my bike the tank was so rusty it would clogg the carbs everytime it ran im dont know how bad yours is but my was real nasty the bike sat for five years with barely any fuel in the tank so i think this should work for you you get a bottle of clr and a pretty good size package of bbs i used steel but copper would probably be fine first get as much of the gas out of the tank as possible and then mix clr with boiling water in equal amounts or maybe just a little more clr than water in the tank then pour in your bbs you dont need a ton but you should use a good amount to help knock the rust of the walls of the tank shake it and slosh the liquid and bb mixture all around the tankfor awhile take the gas cap of every 3-5 minutes between shaking and check the inside of the tank with a flash light to see how its working after it looks fairly decent drain your mixture out of the top of the tank its gonna take some doin but eventually you will get all the bbs out once its all out get a better look at the rust left over if the majority is gone you could probably just rinse the rest out with clean gas but if theres alot you should repeat the first step you may not need bbs the second time around but thats up for you to decide after all that if the tank looks pretty good take your petcock of and take it apart and clean it really good then put it all back together put some gas in it and run it through the tank into a clear bottle to see how clear it is if it looks good put it on the bike and try it out although if it was ran on the bike while it was rusty you may want to clean the carbs first and you also may want to put an additional fuel filter between the tank and the carbs well thats the whole story it worked for me so it would probably work for you but it is tough work but worth it if you ask me anyway good luck

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emperorspartacus
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Re: fuel tank issue

Postby emperorspartacus » Sun Jul 11, 2010 10:36 pm

I took Jeremy's procedure and edited it so I could understand it better. I'll try this procedure tomorrow. Does anyone have any suggestions for sealing the tank after it's shiny and happy?

I just fixed this problem on my bike. The tank was so rusty it would clog the carbs every time it ran. I don’t know how bad yours is, but my tank was really nasty. The bike sat for five years with barely any fuel in the tank so I think this should work for you.

1. Get a bottle of CLR and a pretty good size package of BBs. I used steel but copper would probably be fine.
2. Get as much of the gas out of the tank as possible. Remove the petcock and plug the tank if you don't plan to replace the petcock. The BBs will likely smash the screen and render the petcock useless.
3. Mix CLR with boiling water in equal amounts (or maybe just a little more CLR than water) in the tank. Pour in your BBs; you don’t need a ton, but you should use a good amount to help knock the rust off the walls of the tank.
4. Shake the tank to slosh the liquid/BB mixture all around the tank for a while. Take the gas cap off every 3-5 minutes and check the inside of the tank with a flash light to see how it’s working.
5. After it looks fairly decent, drain your mixture out of the top of the tank. It’s going to take some doing but eventually you will get all the BBs out. Once they’re all out, get a better look at the rust left over. If the majority is gone you could probably just rinse the rest out with clean gas, but if there’s a lot you should repeat the first step. You may not need BBs the second time around but that’s for you to decide.
6. Take your petcock off, take it apart, and clean it really well. Put the petcock back together and reinstall it on the tank.
7. Put some gas in the tank and run it through the petcock into a clear bottle to see how clean it is. If it looks good, put the tank on the bike and try it out (although if the bike was run while it was rusty you may want to clean the carbs first and you also may want to put an additional fuel filter between the tank and the carbs).

That’s the whole story. It worked for me, so it would probably work for you. It is tough work but worth it if you ask me. Good luck!
Last edited by emperorspartacus on Mon Jul 12, 2010 11:04 am, edited 1 time in total.
There are old bikers. There are dumb bikers. There are no old, dumb bikers.

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Volker_P
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Re: fuel tank issue

Postby Volker_P » Mon Jul 12, 2010 6:02 am

Thanks, the edited version makes it readable much more easy.
But the abbreviations are difficult for me.
"CLR" is just "cleaner" or some specific chemical?
"BB" probably means bearing balls?
And one add to the list after #2: Remove the fuel cock and find another plug as this procedure probably will smash the fuel cock filter screen in the tank.
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emperorspartacus
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Re: fuel tank issue

Postby emperorspartacus » Mon Jul 12, 2010 11:02 am

"CLR" is a brand of cleaning product... it stands for "Calcium, Lime, and Rust" cleaner. "BBs" are small metal balls used in air rifles and pellet guns.

Good point on the petcock screen. Above procedure has been edited to include that step.
Attachments
clrproduct.jpg
CLR cleaning product.
clrproduct.jpg (29.22 KiB) Viewed 6177 times
copperhead1000.jpg
BBs
copperhead1000.jpg (39.39 KiB) Viewed 6178 times
There are old bikers. There are dumb bikers. There are no old, dumb bikers.

View my 1980 CB650C rebuild here.

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Volker_P
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Re: fuel tank issue

Postby Volker_P » Mon Jul 12, 2010 12:19 pm

Thanks for the helpful illustration.
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

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emperorspartacus
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Re: fuel tank issue

Postby emperorspartacus » Mon Jul 12, 2010 6:15 pm

There was another suggestion in another thread that involved the same procedure, except kerosene or diesel fuel was the cleaner and you use screws instead of BBs. I think the screws will probably work better. Maybe I'll try both at the same time.
There are old bikers. There are dumb bikers. There are no old, dumb bikers.

View my 1980 CB650C rebuild here.

Gunny
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Re: fuel tank issue

Postby Gunny » Sat Jul 17, 2010 2:38 pm

Diesel or kerosene is what I've used for years since it has a high flash point, thus avoiding the possibility of a spark blowing you to the moon. I use drywall screws because they have nice sharp edges that help scrape the rust off. Nails or machine screws would probably work just as well. Ive never tried CLR but have seen on several forums that it works pretty well.

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emperorspartacus
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Re: fuel tank issue

Postby emperorspartacus » Wed Jul 21, 2010 2:40 pm

Before
Image

After
Image

Used an old, completely blocked petcock to stop up the tank during cleaning
Image

The gunk that came out, including the fuel I used to rinse the tank
Image

For good measure, I threw in a handful of nuts along with the BBs. Someone on [url]forums.sohc.net[/url] suggested using a length of chain, as it is easier to get out than 1000 individual BBs
There are old bikers. There are dumb bikers. There are no old, dumb bikers.

View my 1980 CB650C rebuild here.

davesee
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Re: fuel tank issue

Postby davesee » Wed Jul 21, 2010 9:17 pm

i hope you keep documenting this...i have an '80 standard/custom mix as well.

good luck!


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