gas tank swap - ideas / thoughts

[bacos]

So, it seems the dealer lost one of the rubber mounting bushings at some point and must have decided "aw let's just screw the thing in place tight without it". I can't explain what happened after; I am guessing the mounts were stressed in a way they didn't like, and I'm now getting seepage around the welds on the left side. Not a lot, but, well, more than zero. I don't know if this is one of those "known things that happens" or not. I haven't looked closely at it - all I know is that I stick my hand up there under the tank by the mount and it comes back slightly wet and smelling of gas. It seeps barely a little just sitting there; it seeps more when running.

 

So bike and I are going to travel back to the shop in a truck. Doesn't seem like something worth taking any chances on. Once I get it back to the shop and pull it I can take pictures and comment more accurately.

 

(No, it wasn't me. This is the first year I've done any more to it than change the oil. This is the vacation bike, I'm supposed to be vacationing not wrenching. At least now I know why when I picked the bike up this year, the tank was almost empty, which was weird because I never leave the tank empty. The bike is stored in a huge warehouse with 100 other bikes and open windows, so no, no one would have noticed the smell. And yes. I did notice the missing rubber bushing when I swapped out the hoses last week. I was irritated by it, but my focus was elsewhere, the tank was empty so there was no seepage to see at the time, and I used the old "well it was like that before so it must be fine" line.... see if I ever do that ever again.)

 

 

Fortunately, I have a donor bike I can grab a replacement tank off of. However, it's sat there for 7 years quietly corroding in an attic. I do know the bike only had 98 non-ethanol in it, but it did sit there for a long time. I can go buy another used tank, there's plenty around, but, well, this one is paid for.

 

I am planning to swap the fuel pump/filter rig out from the running bike. If someone wants to tell me now would be a good time to replace the pump then ok I could go scrounge one up but I'm not sure how inclined I should be. 24 yrs but only 90k.

 

The gas dripped down onto the main wire bundle that runs along the left side, and the sheathing is toast. I think the wires are still ok. I am thinking... wrap them with electrical tape? better ideas? Wash the whole thing down first to get any last gas out? Engine cleaner?

 

Clean the tank? With what? Hopefully it hasn't rusted.

 

I suppose I have to replace the vent lines. That's fine, I actually have new vent lines and clamps.

 

What am I not thinking about?

 

[dirtrider]

17 minutes ago, bacos said:

So, it seems the dealer lost one of the rubber mounting bushings at some point and must have decided "aw let's just screw the thing in place tight without it". I can't explain what happened after; I am guessing the mounts were stressed in a way they didn't like, and I'm now getting seepage around the welds on the left side. Not a lot, but, well, more than zero. I don't know if this is one of those "known things that happens" or not. I haven't looked closely at it - all I know is that I stick my hand up there under the tank by the mount and it comes back slightly wet and smelling of gas. It seeps barely a little just sitting there; it seeps more when running.

 

So bike and I are going to travel back to the shop in a truck. Doesn't seem like something worth taking any chances on. Once I get it back to the shop and pull it I can take pictures and comment more accurately.

 

(No, it wasn't me. This is the first year I've done any more to it than change the oil. This is the vacation bike, I'm supposed to be vacationing not wrenching. At least now I know why when I picked the bike up this year, the tank was almost empty, which was weird because I never leave the tank empty. The bike is stored in a huge warehouse with 100 other bikes and open windows, so no, no one would have noticed the smell. And yes. I did notice the missing rubber bushing when I swapped out the hoses last week. I was irritated by it, but my focus was elsewhere, the tank was empty so there was no seepage to see at the time, and I used the old "well it was like that before so it must be fine" line.... see if I ever do that ever again.)

 

 

Fortunately, I have a donor bike I can grab a replacement tank off of. However, it's sat there for 7 years quietly corroding in an attic. I do know the bike only had 98 non-ethanol in it, but it did sit there for a long time. I can go buy another used tank, there's plenty around, but, well, this one is paid for.

 

I am planning to swap the fuel pump/filter rig out from the running bike. If someone wants to tell me now would be a good time to replace the pump then ok I could go scrounge one up but I'm not sure how inclined I should be. 24 yrs but only 90k.

 

The gas dripped down onto the main wire bundle that runs along the left side, and the sheathing is toast. I think the wires are still ok. I am thinking... wrap them with electrical tape? better ideas? Wash the whole thing down first to get any last gas out? Engine cleaner?

 

Clean the tank? With what? Hopefully it hasn't rusted.

 

I suppose I have to replace the vent lines. That's fine, I actually have new vent lines and clamps.

 

What am I not thinking about?

 

Afternoon bacos

 

Without actually seeing the damaged spot it is difficult to advise on a repairs but most repairs will blemish the area around the repair. 

 

That used tank you have is probably the best bet if it isn't all varnished up inside. 

 

On the harness repair, electrical tape is not a good repair, it will sort of work but not the best way. Instead use a dedicated wire harness covering  tape.     

 

Or you can slide on some split convoluted wire harness covering (I use this on lot in out of sight areas as it it tough & used by a lot of OEM vehicle manufacturers. It looks a lot better than a poor tape job. It is difficult to properly tape a harness with the harness in place on the motorcycle. 

 

 

 

 

 

 

[bacos]

how much do I care about varnish if none of the vent holes are plugged? I imagine there are chemicals to clean out the varnish but that sounds messy and I dunno that my friend’s shop is set up to dispose of the resulting gunk. In the case, I can order another tank from Berlin for not all that much. 

[dirtrider]

1 hour ago, bacos said:

how much do I care about varnish if none of the vent holes are plugged? I imagine there are chemicals to clean out the varnish but that sounds messy and I dunno that my friend’s shop is set up to dispose of the resulting gunk. In the case, I can order another tank from Berlin for not all that much. 

Morning bacos

 

The problem with varnish from old stale fuel is that it can eventually dissolved (or at least some of it can be dissolved) by new fuel or the additives in the fuel then that gunk can then end up in the fuel filter or even get through the filter then into the fuel injectors.

 

You need to figure out if that stored tank is still usable, and/or if it can cleaned out & used without worry. 

[Hosstage]

Any chance to weld the original? It will get discolored a bit, and the welds may show some, but a little touch up paint would help smooth out the look. The surrounding area can be clayed to try to prevent heat transfer. This if the donor tank proves unusable.

[wbw6cos]

You may check with a local radiator shop to inquire if it is possible about a repair.  For my tank on my R 1200 C, I did not find a local radiator shop willing to take on the task due to liability on paint damage.

 

 I eventually sent it off to FL to get it repaired and re-lined at a shop that performed the repair without damage to the paint.   The seam was leaking (left side, near mounting flange) and the repair involved heating lead, I believe.  After that repair, the interior was cleaned and lined.   It was not cheap, with shipping and the actual repair, but it was better than the NLA parts issue that I frequently encounter with older BMW bikes, specifically the R1200C.  Disclaimer:  the R12C was in production for about 5 years, which adds to the lack of availability.   The procedure for the tank repair and lining was not a quick one, either.   I will not bore you with the details. 

 

If you find the spare tank is good enough to use, then you should source a solution for repair on the original tank.   

[bacos]

Well, it turns out the donor tank was just fine. Apparently it's common enough that gas sits in a tank 7, 10 years here, and nothing happens.

 

There is no obvious break at all anywhere. There is a clear track of gas/dirt coming from underneath the mount, but where underneath who knows. Since spare used tanks go for $150, there's just no odds in attempting to fix it. So, this one goes in the trash and that's that.

 

However, so while it was on the hoist I decided to pull the starter and just check the clutch splines.... which... are shot. Right around that 1" at the clutch edge mark. So I've spent several days of my vacation fixing a bike ... that I don't dare ride for the rest of the trip anyway.

 

This wouldn't be so bad if I hadn't _already_had the bike trailered home once this vacation!

 

 

For what it's worth, I got some of that tape and re-wrapped all of the harnesses. It's definitely slick stuff.