Was the gas tank coated from the factory?

[djohnson81]

I am replacing the lines in my tank of my 2000 R1150GS. There is a flaky coating on parts of the inside. Not sure if this is just build up from old fuel or if it was a factory coating or someone added it on purpose. I bought this bike a year and a half ago, not sure what has been done. The in tank lines are breaking off as I am taking them out, and there was no fuel filter and some lines were just floating around in there. Amazing it was still functioning. Thanks for the help.

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[Rballou53]

My 2004 Rockster has a reddish coating inside the tank. I think it came from the factory that way.

 

[52184]

Yes, the tank was coated internally and by the looks of your photos yours needs a refresh. Copy the following string into whichever web search engine you prefer and you’ll get a number of links to follow for information on available coatings and the process for doing the job:

site:https://forums.bmwmoa.org gas tank lining

Best,
DeVern

 

[djohnson81]

Has anyone removed the coating and left the tank uncoated?

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[69zeff65]

I've done two tanks

I did the R 850R Scrambled tank and an 1100 GS tank, it took a while for both just to get all the old crap out and dry the tank out for a proper reline in Red Kote. I made a couple blanks or plugs to block off the cap and fuel pump opening and went to town on removing the remnants of the old liner and ensuring they were clean and degreased. Sometimes it is better to just clean the tank really good and change the filter often.

 

[20774]

Has anyone removed the coating and left the tank uncoated?

I presume the tank is made of steel?? If you leave it uncoated, you'll eventually get a layer of rust develop which can damage the tank over time.

 

[gsaddict]

The tank factory coating is flaking off. Common on this vintage of GS/A.
Best for long life if stripped and recoated.

The floating line (top picture) goes to a tee and 2 ends drop to the bottom of each tank lobe.
Gas is evacuated to the the top of the hose and then plugged by the bolt.
Gas will siphon back and forth between the lobes effectively extending the range by emptying the left lobe.
This mod was named by some as the "syphon sucker" which was done for GS models.
The GSA tank has an external balance hose between the lobes.

 

[djohnson81]

Thanks

Thanks for the info GSAddict, I was a bit lost trying to figure out what all of the lines were, as there seemed to be more than what the parts fiche and manual showed. The previous owner had removed the charcoal canister as well. So to get the "syphon sucker" to work again, I would use suction to bring fuel up to the short top tube and plug it?

 

[djohnson81]

Best solvent for original liner removal?

I see in other posts various solvents to remove the liner, anyone have first hand experience?
Thanks

 

[gsaddict]

Thanks for the info GSAddict, I was a bit lost trying to figure out what all of the lines were, as there seemed to be more than what the parts fiche and manual showed. The previous owner had removed the charcoal canister as well. So to get the "syphon sucker" to work again, I would use suction to bring fuel up to the short top tube and plug it?

Yes, that's it.

 

[djohnson81]

Update

Ok, I have tried just about every chemical available to strip the inside of the tank. I have used a Scotch Brite pad to take off as much loose liner as I can get to. I tried a dremmel with a flexible extension to try and get to more of it. I have used agitation with screws and chains by themselves and in conjunction with paint strippers and acetone. I used a pressure washer and 175 psi compressed air. There are still remnants of tank liner stuck on the inside walls of the tank. I Have not used a heat gun in fear of bubbling the paint on the outside of the tank. My question is- would the liner give up it's adhesion before the paint starts to bubble?

 

[gsaddict]

I'm saying NO!

Try Drywall screws, they are very sharp and hard.

 

[jrogers]

Guy on another site put loose nuts and tumbled the tank for awhile. Also another guy suggested vinegar soak and then the nuts. Haven't done it myself.

https://www.advrider.com/f/threads/bmw-r-r-thread.844612/page-574#post-46788435

 

[52184]

All of the interior lining must be removed or the new lining will delaminate. If you’re having difficulty removing all the old liner and feeling like you’ve hit your limit, there are companies that can to the prep and relining for you. A Google search for “motorcycle gas tank relining service” will pull up a number of vendors to be explored. Pricing and warranties may vary, of course, so some research pays off.

Best,
DeVern