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Yikes, problems with rusty tank!

Jethro

Jethro

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I noticed that when I got my bike there were little tiny specks of rust on the inside of the otherwise new looking tank. Well, the other day I pulled my carbs off for some work and the float bowls drained some nasty stuff- red goop. I cleaned it all up and put it back together, thinking that maybe I got some wet gas and the rust was temporary. It's been two years like this, no problem. I filled the tank up and figured it would be the end of it.

Well, yesterday as I was riding home, the bike starts to run poorly on the pilot circut, like it's starving for fuel fuel. It idles fine, pulls great on the mains, but at 1/8 throttle I have some pretty bad bogging. I'm sure it's that gunk in my float bowls again:-| If it's not one thing, it's another.

I ride the last mile keeping it at the 1/8 throttle, purposly making it bog and cut the power as I pull into the driveway for a plug read. The plugs show me a patch of red on the insulator and firing end, and I mean red like bright, candy apple red. Otherwise the plug looks good. I'm guessing this is the rusty goop in my tank and float bowls. Does rust look like this when it invades a gas tank? Like a red goop? I ask becasue recently I fixed my broken sending unit float with JB Weld, which I have been told is just fine for fuel systems.

So looking into the tank, it's still pretty clean for what I can see, just some tiny spots of rust on the otherwise clean metal.

Queston is, should I do a full POR-15 sealant job, or do you think I should try a flush only? There are no leaks whatsoever, I'm sure there aren't any pinholes. A search I did for tank sealant brought up differing opinions about sealing as opposed to just a rust treatment. I am opposed to a tank sealant becasue I had a bad experience with Kreem. Never again there.
 
Jethro,
I just finished cleaning my tank before installing a new Pingel. I never thought my tank had much rust until I decided to check it out closely. I just used some pea gravel to knock the loose rust off the surface then used phosphoric acid to get rid of the harder rust. After the first acid treatment I had a semi-circle chunk of rust about 1/8" thick and about 2" across come out in one piece. I ended up doing two acid washes followed by a rinse with water. After that I used a blow dryer to dry the tank out. Since I have some work to do on the bike I used some naptha and motor oil mixed to coat the inside of the tank for protection. I drained that and once the naptha evaporates I should have enough of an oil coating to protect the tank until I'm through modding.
 
Thanks Billy. I'm gonna be filling the tank right away, so I wouldn't need to do the naptha/motor oil thing, right? Just wash with phosphoric acid (I've heard MEK is good too) and rinse/dry and fill with gas?
 
Jethro, I have phosphoric acid for you...and a "neutralizing" agent as well...MSN me
 
Jethro said:
Thanks Billy. I'm gonna be filling the tank right away, so I wouldn't need to do the naptha/motor oil thing, right? Just wash with phosphoric acid (I've heard MEK is good too) and rinse/dry and fill with gas?
Click to expand...
As long as you fill it up right away don't worry about the naptha/oil rinse. I don't think the MEK will touch the rust though. Phosphoric acid works fine and a gallon is only about $13 at Home Depot. I sealed up the tank with duct tape then used about one quart of acid at a time. Slosh it around so the entire tank gets coated inside then drain the acid and let it sit for a few hours. Rinse with water then acid wash again.
 
well, having dealt with lots of rust before, etc, i spoke with Jethro, and it doesn't quite sound like rust to me...I have dealt with some SERIOUSLY rusty moped tanks in the past, kreme'ing, por15ing, concrete etching etc whatever needs doing inside of them, and never had "goop/gel" form from rust...goop/gel forms by time's effect on gasoline, but knowing jethro, gasoline gets refreshed quite often in his bike...so I am not sure that it is rust...
 
Looks like I have a date with Mr. POR-15.

Draining the tank into a funnel with a cheesecloth paint filter brought forth about 1/16th of a lb of rust. Nasty. Float bowls were FILLED with rust, it's a wonder I made it home. Anyone who has done the POR-15 job have some tips? Can it be done in a single evening? I have the tank drained and off the bike, sprayed some fogging oil in there for the time being.

If I can't get it done in a night, I'm out of the Cabot Trail run. I have no time between here and there...
 
Jethro said:
Looks like I have a date with Mr. POR-15.

Draining the tank into a funnel with a cheesecloth paint filter brought forth about 1/16th of a lb of rust. Nasty. Float bowls were FILLED with rust, it's a wonder I made it home. Anyone who has done the POR-15 job have some tips? Can it be done in a single evening? I have the tank drained and off the bike, sprayed some fogging oil in there for the time being.

If I can't get it done in a night, I'm out of the Cabot Trail run. I have no time between here and there...
Click to expand...
Jethro,
Give the phosphoric acid a try. It only attacks rust and won't harm solid metal. It is the acid that comes in Kreem kits and is the active ingredient in Ospho. It converts iron oxide (rust) into iron phosphate which is fairly rust resistant.
 
Billy Ricks said:
Jethro,
Give the phosphoric acid a try. It only attacks rust and won't harm solid metal. It is the acid that comes in Kreem kits and is the active ingredient in Ospho. It converts iron oxide (rust) into iron phosphate which is fairly rust resistant.
Click to expand...

Are you sure? I had like a 1/4 cup of metal fall out of the tank. It's a mess! With the carbs off, and looking into the engine manifold, the ports and what I can see of the valve stems are all covered in a red, rusty mess!! I simply can't risk trashing my engine. It's like a powder that is going through the engine.
 
Jethro,
it won't be done in an evening unfortunately....you need a full day to do a proper kreem/por15ing....

i do reccommend the name brands over the "phosphoric acid" trick....the stabilizing/coating agents are very useful...also using the acid can open up pinhole leaks that weren't there before, and without the coating agents, won't reseal...
 
Fuel tank reline

Fuel tank reline

Been reading about your tank situation, I live in Il. and have 2 81 bikes that sat for 20 yrs. Tanks were rust cans inside, found a rad. shop to
clean out and reseal. They did a fantastic job for $80.00 each. I suspect
and can only hope that the days of rust are over for these guys.


bmac
 
I've called 3 radiator shops here in NH, the lowest quote I've gotten was $200 and they all say chances are good I'll need a repaint afterwards.

The shop down the road has the Kreeme stuff, but I had a bad experience with that junk. Looks like I am missing the Cabot Trail trip...
 
Jethro,
Do a Google search for phosphoric acid and gas tank rust. I know you are reluctant to try it but as long as the tank is fairly sound it will work for you. I was hesitant to use the stuff at first but it worked great.
 
I agree. Use the acid... at least as a temporary treatment. That will get the majority of the stuff out. Then maybe you can put an in-line gas filter in until you get back from the Cabot ride.
 
jethro, for a temp fix, definitely go with phosphoric...1:1 solution of the acid/water, then do the 1:4 of bakingsoda/water to neutralize it...
just pour the acid in, and let it sit in there for about half an hour, or better yet slosh it around a bit too...then neutralize it....you will still be able to do the cabot trail ride then
 
Yeah, I'm gonna try it I guess, but I'm real nervous. My friggin valves are all covered in STEEL dust. That's not exactly good for the engine. And if this happens in Cape Bretton, I'm pretty screwed, can't exactly ask the little woman to come pick me up with the truck 1000 miles away...
 
renobruce said:
I agree. Use the acid... at least as a temporary treatment. That will get the majority of the stuff out. Then maybe you can put an in-line gas filter in until you get back from the Cabot ride.
Click to expand...

I don't think an inline filter would do the trick. The stuff I scraped off the float bowls was like powder. It actually painted my sprak plugs red, and the gas drained from the bowls was like red paint. No solid rust in there at all, my Pingle seemed to hold back the big stuff. It now looks like someone held a can of red spray paint in my manifold ports.

I'll do the phosporic acid thing tonight, nuetralize it and fill it immediately with gas. Just don't know how I am gonna be sure I'm not sucking in liquid metal in the meantime.
 
i dunno bro...maybe putting the cabot trail ride off might be a good idea...if you are that worried, you always have that option..better to put off the ride then to end up in a place far far away, and ****ing off SWMBO(She Who Must Be Obeyed)
 
Make sure after you clean it you get all the water out of the tank. Either use a blow drier and roll the tank every once in awhile to spread out any water residue or get some denatured alcohol to slosh around in it to dry out the water left behind. I think you are going to be pleasantly surprised with the results. Tank the float assembly out and the petcock. I just used duct tape to seal up the filler, float assembly, and petcock holes.
 
Jethro said:
I don't think an inline filter would do the trick. The stuff I scraped off the float bowls was like powder. It actually painted my sprak plugs red, and the gas drained from the bowls was like red paint. No solid rust in there at all, my Pingle seemed to hold back the big stuff. It now looks like someone held a can of red spray paint in my manifold ports.

I'll do the phosporic acid thing tonight, nuetralize it and fill it immediately with gas. Just don't know how I am gonna be sure I'm not sucking in liquid metal in the meantime.
Click to expand...
You can get phosporic acid cleaning products, I just used one on some bolts. The stuff I used is like a green slime that coats everything it hits then it starts bubbling and stuff while it eats up the rust.

you can also get really fine fuel filters that should take out any crap that goes through for a few days. If it is small enough to make it through it should not cause too much of a problem.

As far as the Cabot Trail ride, you have two weeks man, you will have her ship shape by then! If I guess right you won't sleep well at night until she's fully repaired!

EDIT: if you use one of the paper type filters (think old snowmobiles) if there is rust it should tint the paper.
 
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