R1100RS Tank Bolt Misalignment

[Christo]

Greetings all. Thanks in advance for any advice!

I'm starting to have a lot of trouble aligning the right side tank mounting bolt after removing for service. This after a year or two not removing. The last time, I had to use a stout screwdriver to align, then something to hold the tank forward, then tap the bolt in. Now, it's about 1/8" off no matter how hard I try o reseat the tank, and I feel like reaming the hole larger, but worry about alignment of body panels. I checked, and there is nothing in the cavities where the rubber mounts seat in the tank, and no other obstruction I can see. Is this an issue of the rubber mounts getting old and stiff? Or is there some little wire blocking the tank somehow?
(see attached photo)
 

[dirtrider]

24 minutes ago, Christo said:

Greetings all. Thanks in advance for any advice!

I'm starting to have a lot of trouble aligning the right side tank mounting bolt after removing for service. This after a year or two not removing. The last time, I had to use a stout screwdriver to align, then something to hold the tank forward, then tap the bolt in. Now, it's about 1/8" off no matter how hard I try o reseat the tank, and I feel like reaming the hole larger, but worry about alignment of body panels. I checked, and there is nothing in the cavities where the rubber mounts seat in the tank, and no other obstruction I can see. Is this an issue of the rubber mounts getting old and stiff? Or is there some little wire blocking the tank somehow?
(see attached photo)
 

Evening  Christo

 

No way to know for sure what is causing the issue from just an internet picture.

 

It might be a swelled rubber mount issue, or a tank interference issue, or subframe issue, or a combination of things. 

 

About all you can do is carefully inspect things then make an informed guess at what is causing the issue.  

 

If you can't find a smoking gun then try forcing it into alignment, then tighten the attaching bolts, then loosen that side subframe attachment bolts (to allow it to neutralize), then re-tighten the sub frame bolts (it's possible the subframe has migrated slightly) 

[Christo]

Hello DR,

 

Thank you for the suggestions. I wasn't thinking it was bolted to the subframe and that the subframe could be shifted. Two possible causes are the time I did the tranny swap (which you graciously helped with) and also the time I hit a pothole/slot in the pavement in a construction area so hard that it made my sternum hurt, but didn't seem to cause any damage. But that was years ago and I didn't have as much trouble then. I'll check underneath the tank better also. 

Thanks!

[Jim Moore]

Mine won't align either. I use a zip-tie instead of the bolt.

[Christo]

7 hours ago, Jim Moore said:

Mine won't align either. I use a zip-tie instead of the bolt.

Interesting. Good to hear I'm not alone. I wondered if the bolt was a structural feature, in case of sudden shifting. But the seat would prevent it from sliding back, and a zip tie like you said. Also, taking a dremel to the hole. But like DR suggested, I'll make sure it is not impinged first. 

 

[Fir Cologne]

The rubber insert needs the metal liner, I get mine out of synch all the time, squashes the rubber. I have quick releases, tanks bee off so many times...

[Christo]

I wanted to follow up on this older thread.

 

After overhauling the fuel tank innards for the first time and having the tank off multiple times, I finally noticed a wire jumping into position to block the rubber mounts when seating the tank against them, making the  right side tank mounting bolt hard to insert. 

 

I pulled that wire away and secured, and now the bolt goes in more easily! So if you have this issue, really get under there and make sure the tank mount channels are clear.  

[Danny01]

Just to add. I had a similar problem years ago when I changed the brake pipes to braided stainless. The rear bolt on the tank was difficult to insert and the fairing panel fasteners didn't line up properly.

The seat also wouldn't push fully forward into the slots.

I took the bike to a BMW dealer to look at the seat problem and they said that's just how the bike is after an inspection.

 

Eventually I concluded that the tank had possibly swollen due to the effects of ethanol in the fuel. It was a problem on some Ducati's too.

Seems to be better now that I use E5 or Super Unleaded. Ethanol free fuel would be best but not sure if that's available.