Introducing my new old R65 (with fuel leak...)

[RgR]

Hello everybody!

I am new to this forum, so I would like to introduce myself. I live in Holland, i'm 31 years old, and two weeks ago I bought a BMW R65 (built in 1983). The bike looks really nice and I was really very happy with it.

Unfortunately, yesterday when I wanted to drive back home from work, I suddenly saw a HUGE amount of fuel leaking out of the tank.. When I looked closer, I saw a hole (actually, two little holes), no longer covered by paint..

When I looked closer, I saw some more 'bubbles' in the paint of the tank, so I think it is a matter of time before the fuel will find more wrong ways out  

As a temporary fix I tried nail polish (I heard that works sometimes) and Griffon Epoxy Repair, but it didn't really feel like it adhered very well to the tank.

I think I need to buy a new tank. I couldn't find much on the dutch version of ebay (marktplaats), so could you tell me if it is also possible to mount a tank from another boxer-model?

[montmil]

Welcome to the herd, RgR.

Your fuel tank is the victim of internal rust.

Water/condensation has collected and remained in the lower portion of the tank for an extended period -perhaps years- and has finally developed the fatal pin holes. Both sides can be attacked. Look for tiny blisters in the paint along the lower seams.

You may be able to fit a tank from an R80 without any chassis or tank mods.

You have a nice looking R65 with the twin front disc brakes. The square master cylinder does date it as the later style but your flat top Bings are unusual on the '83. 1979-80 bikes had the flat tops -unless the Euro-spec R-bikes are different from the North American equipment.

May be an exercise in frustration in attempting to fix your current tank. No telling how far the interior rust has progressed. Find a good tank in rust free condition and paint it black. Inspect the interior with a flashlight and mirror. The tanks have a red-ish rubbery coating on the inside. Find one with intact lining.

Remove and drain your new R65's fuel tank annually and let it dry out completely. Just turning the petcocks on won't do it.

Keep us posted on what transpires.  [smiley=thumbsup.gif]

[steve hawkins]

I had a similar issue with my 79 R65 when I first got it.

I got someone locally to braise the tank up.

The problem is that if you have one hole, the likely hood is, that there will be others waiting to show themselves.  Both sides.  As it was in my case.

The chap that did my tank, did a thorough job, and I have not had any issues for the last 10 years.

So they can be repaired.

But it would probably be cheaper to source another tank, and you might be lucky and source one the right colour.  

Get into the habit of removing and draining the tank every year or two, to remove any rubbish, etc, from it.  Water will always collect at the lowest points, and if left, as in this case, do this sort of damage.  Too much washing of your bike can also be a way of introducing water  And please be careful with any high pressure sprayers - always a good way of introducing water to places where its not wanted

The problem with R80/100 tanks is that I think they are a little shorter than the standard R65 tanks, so there will be a gap between front of the saddle and the rear of the tank.  This might be unnaccetable if you are keeping the bike standard.  but not if you plan to make a 'special' out of it.

Looks like you have an early 'post 81' bike.  With many parts from pre 81's along with the post 81 engine and gearbox.  As stocks needed to be used up.

If you are patient then something will pop up.

Cheers

Rev. Light

[montmil]

A very useful site to determine the month and year build date of your BMW motorcycle. All you need to know is the VIN.

http://www.realoem.com/bmw/select.do?kind=M&arch=1

[nhmaf]

An R80ST tank (though a rather rare model this side of the pond) should fit without modifications, though other models may need various custom tweaks to work.   The R45 (more common in europe that in North America) also used the exact same tank as the R65.

There are various methods to get the rust out of the tank - yours *might* be saved with careful rust removal treatment, braizing up and relining with various fuel tank treatments such as POR-15, Kreem, or others on your side of the pond.

[Luca]

+1 on saving the tank you have.  It really might not cost you more than a replacement  Though brazing might ruin the current paint, it looks dent free.  Better to have all steel than use filler on a solid but dented tank.  Plus, it's part of the bike.  You might be more satisfied with a real repair than a replacement part.

If you do decide to repair it or have it repaired, any good welder should know that placing a piece of copper against the tank will act as an excellent heat sink, minimizing the chance for warping (and maybe even paint damage)

various fuel tank treatments such as POR-15

can't say enough about that stuff.  We have a 300 gallon tropical saltwater fish tank system (sump included)  The rock tank/sump in the basement is on a steel frame painted with POR-15, as is the metal brace I welded up to keep it from bowing out when full of water.  6 months of salt water and salt creep and no rust yet!

[RgR]

Thank you very much for your good advices! I finally managed to temporary stop the leaks with the epoxy-repair-stick, so I could drive my bike back from my work to my home and my R65 is 'on the road' again for now.

Good to hear that it might be possible to save my tank. I will search for a good welder in my neighborhood, and in the meantime I will also keep looking for second hand tanks of one of the mentioned models on the net.
Thanks a lot!

[Bob_W]

Radiator shops commonly solder leaks. I used one to remove old coating, clean, repair and pressure test. After two weeks soaking inside and out looked like new. Cost was $75.00. Of course the outside paint was gone and I got a surprise, the tank had a large dent covered with Bondo. The shop owner offered me old old Bondo plug but I declined.
I followed Snowbum's advice and used a phosphoric acid etchant on the inside after it started to rust. Rust is now a grey coating.
Bob

[Dave 2]

I also had the pin whole leaks on my 1983 R65LS. The BMW dealer in Maine sent it out to a radiator shop which cleaned the interior and than coated the interior with an epoxy which has sealed the tank. I have had no leaks in the past few years. Good luck with your bike. D2

[balibeemer]

I had the same problem. And this was my solution, which took a total of 4 days:
1. Remove the tank and inspect it for a tank liner. Remove the petcocks and plug the holes with wine bottle corks
2. If there is no coating on the inside of the tank, plug the holes with anything like soap, araldite etc and fill it with 20 liters of water. Add 2 liters of phosphoric acid and leave it for 24 hrs.
3. Drain the water acid mix. refill the tank with 25% bicarb of soda and 75% water. ( This neutralises the acid) Leave it for 20 mins.
4. Spray a can of WD 40 into the tank and slosh it around to de water the inside.
5. pour 2 liters of thinners into the tank and slosh for 5 mins to remove the WD 40
6. Put a 12 volt lightbulb connected to a battery into the talk and in a dark area inspect the tank for holes. Mark them.
7. Prep the area of the holes so that you can apply metal based epoxy paste to the surrounding areas, and covering the holes. Allow to cure properly.
8. Mix up a 2 liter can of nitrocellulose epoxy primer, using 10% more hardener than recommended. Make sure that you plug the petcock holes and mask the threads. Slosh the primer around the tank for 5 min. and then drain it out via the petcock holes.
9. Borrow your wife's/mothers/ girlfriends hairdryer and turning onto low heat, put it into the filler hole and leave it there for 3 hours. Then allow the epoxy primer to cure for 24 hours.
10. Refill fill the tank with water to check for leaks - there shouldn't be any.

I used this method in 2009 and
A) The tank does not leak.
B) the epoxy is all still there and it HAS NOT affected the engine performance.
C) I have a lovely pale grey inside of the tank.

That's it!
[smiley=thumbsup.gif]

[RgR]

Last week I more or less followed balibeemer's advice. I hopefully removed the rust and then cleaned the tank thoroughly, and then covered the holes on the outside with a new layer of epoxy-paste. Then I used Tank Cure to cover the inside. After that, I sprayed black paint over the epoxy-paste.

I now have to wait a few days more before the Tank Cure has fully 'cured', very exciting..

Thank you all for your advice!

[Tony Smith]

Welcome.
 
If you decide to buy a new tank, set you ebay search to "worldwide" and you will pick up the German and USA sellers. I bought the tank that is now on my project bike from Germany - price plus parcel delivery by DHL was less than I could have bought a tank and had it posted to me in Australia. You are much closer and transport will be less.

That said, I have great success over the years using a product called "Kreem'.

Links below

http://www.ebay.com/gds/How-to-use-the-KREEM-Gas-Tank-Sealer-Kit-/10000000001059206/g.html

http://www.youtube.com/watch?v=dT3vUX7vUGs