[frankenpak]

imported post

Got my carb's back from pistol pete and do not want to take the chance ofgetting particles in the carbs. I noticed some sedement in the bottom of the fuel filter. The filter was fairly new, is this normal? I drained the tank and looked for particles, diden't see anything much. How do I check this thing to make certain it is clean enough befor I re install the carbs. I shined a light in the tank, it look's right nasty but that could be age. I hope that if it doe's need cleaned there may be an easy sollution. Any thought's.

 

[AZgl1800]

imported post

From my perspective, I would look in the tank with a flashlight and see if the tank walls show any sign of rust.

If rust is there, I would definitely clean it.

 

[frankenpak]

imported post

Yes, it look's like rust and the sedement in the bowl look's a rust color. What would be the best thing to do? pull the tank & have it cleaned or try and clean it as is. To pull the tank off requires a bit of work, is this correct? Since this is the third time I have pulled the carb's I don't want to take the chance of messing up the carbs.

 

[RB]

imported post

Yes you have to pull it..several methods for cleaning,,electrolysis, acid, radiator shop..sealing it is another choice por15 or Red-kote, nickel plating or nothing but keep it full of gas.

Lots of threads on cleaning do a search..on POR15 and most of them will show up

 

[cycleman]

imported post

I'm pretty sure that Honda started coating the gas tanks in 77 so I would be careful of what you are actually seeing. If it's bits of black stuff it's most likely some of the coating. I know my 77 has very old original coating that doesn't look the best but it's not rust.

If you take the sending unit out you can get a much better look at what is going on inside the tank. Any moisture/rust would be at the bottom rear of the tank between the rear pickup & rear of the tank closest to the rear tire.

This is the spot where I've noticed rust on older gas tanks that are out of bikes.

 

[frankenpak]

imported post

I took the sending unit out and noticed that to be the worst area of rust, but not so bad as it can't be surface cleaned, I took a scope magnet and drug it throught out the tank, i got only minor deposits of brown rust, no flakes or chipson the magnet. I am thinking of acleaning and wet vac with muric acid or another cleaning solution . This tank look's like it would be hell to remove and summer is just around the corner. What do you think? If there is only minor rust. I would think on older bikes there would be a certain amount of sedement.

 

[sandcastcb750]

imported post

Consider buying another tank off Ebay. They are usually cheap. You're gonna have to pull the tank anyway if the rust can't be removed.

 

[k1w1t1m]

imported post

Since I was too lazy to remove the tank when I acquired my bike, I used a siphon through the filler and sender holes to "vacuum" the tank. I siphoned into a couple of empty gas cans and then let the junk settle. Then I was able to carefully refill the tank. I installed a new filter at the same time. A few miles and regular filter changes should keep me out of trouble for a while.

This will work until I have to or find a better time to remove the tank to clean it out properly.

 

[cycleman]

imported post

You can get as fussy as you want. If there's no obvious signs of rust spots or leaks at the bottom of the tank most of what you are seeing is likely from the top portion of the tank. This most likely happens in all gas tanks when they are left part full. If there is no air then no rust.

I'd give it a good cleaning either by adding fuel & siphon it out or drain via the drain plug. I'd go easy on the acid because it may affect what coating is left in the tank. I guess you could pressure wash it and then let it sit until dry if you wanted to but may cause other issues.

From then on I'd make sure I periodically added some Sea Foam to the tank ( it absorbes moisture) and always fill the tank up to the top if you are not riding for awhile. Also regularly change fuel filter.

 

[frankenpak]

imported post

...I didn't mix the acid all that strong, I left it in about three hours, I drained it 90% then toped it off with water, butwhen I looked in the tank thereseemed like a lot of brown bubblinggoo. Look like something out of my grandfathers still.I will flush it two or three times tomorrow and see what happenes. I thought of filling it back up with kerosene then flushing it back out, but I'm not so sure if that is a good idea. This sort of thing is like taking a chance. And it could be a costly one at that.

 

[frankenpak]

imported post

...I didn't mix the acid all that strong, I left it in about three hours, I drained it 90% then toped it off with water, butwhen I looked in the tank thereseemed like a lot of brown bubblinggoo. Look like something out of my grandfathers still.I will flush it two or three times tomorrow and see what happenes. I thought of filling it back up with kerosene then flushing it back out, but I'm not so sure if that is a good idea. This sort of thing is like taking a chance. And it could be a costly one at that.

 

[RB]

imported post

Try acetone if the gas settle out and formed a black goo the acid won't do much to it..but acetone will; fill up and let it sit for a day or two..turning the tank every few hours to get all the sides..then drain and then acid to clean the metal and then seal.

I just did a tank that was full of black goo/tar like stuff the acetone dissolved the black goo and then the acid took the rust off..

It worked for me..

 

[MS03]

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Thanks for the ideas and comments folks, I have my tank out and I'm going to do mine tomorrow.

 

[frankenpak]

imported post

Actually you are doing it the right way by pulling your tank, so since you have went through all that trouble, I suggest that you do it up the best possible way. Such as cleaning it real good then sealing it if you so think it nessasry. Follow all the info that you can get so as to not mess up the screens and anything else in there. I should of pulled mine, it probably don't take any more time by the time it's over and done and you get a better job with more peace of mind. I'm lazy and also don't have all the know how. Good Luck

 

[MS03]

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Yeah I just started I put water in it the first time and plenty of rust came out.

 

[cycleman]

imported post

I would be careful with any acid or acetone. Not only will they eat stuff you don't want them to eat but it is very hard to ensure they have been totally nuetralized.

These tank linings are impervious to gas but not to other stuff. ie: acids

 

[MS03]

imported post

I'm trying fuel injector cleaner first, it seems to be dissolving the rust pretty good. I'll keep you posted.

 

[MS03]

imported post

It's working pretty good. A couple of questions what color is the coating and has anyone tried radiator flush.

 

[cycleman]

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I'm pretty sure mine is black in colour. The sides where some of the coating has worn off appear more brown.

If it's an aftermarket job it could be almost any colour. Tanks I've had done in the past where done with a clear coloured coating. That's what they use up here where I've had it done. The coating works the same as rust paint in that it no longer allows the air/water to react with the metal.

If when you are done you have rust on the bottom rear portion of the tank ( between the rear screen & back of tank ) I would get it coated if you want to keep your tank. If its cleaned in a professional bath you will have to repaint the tank. Whatevery they use it takes everything off paint, filler etc.

The trouble with buying another tank it may not turn out to be much better than yours.

 

[MS03]

imported post

Thanks cycleman, the tank was a little worst than first thought. The coating came out too easy it just flaked off and a lot of it. It was even on the drain plug so it would not drain. the screens finally came clean but the lines were plugged so I cleared them with compressed air. Unfortunately I'm going to have to go with Acid and get as much as I can out then re-coat it.

I guess since the Bike has not been rode since 1979 that has caused this problem. I saw a tank on ebay and I thought the same is it any better than what I have now.