Happiness short-lived, looking for suggestions

[tod.branko_imp]

So as I finally got the last piece for Joe to pour the fuel and crank it up, the excitement lasted fir about 30 seconds when the fuel start pouring out from the bottom of the tank, i took me a while to disconnect that nasty fuel pump jack, but that time a full gallon poured out. When I finally managed to turn the tank around to have a look at what the heck was happening, I found that the paint guys overtightened the fuel pump screws and one of the bolts cracked. They just left it there still attached so as soon as I twisted it off the bolt stayed in my hand.
Now these bolts are welded to the ring that holds them, does anyone have any suggestion on how to fix this, because at this point I'm a bit clueless.
I feel like I'm gonna need a new tank, do you all have the same feeling?

'14 CB1100 STD 5 speed

[dave]

Hi. I am so sorry this happened to you. An experienced machine shop that can weld could repair this, but it probably wouldn't be cheap. Just a thought: If you could remove the broken stud it may be possible to epoxy a new stud in place. You could braze a fender washer beneath the head of the bolt to give it more surface area for the epoxy to bond to. Insert the bolt with the fender washer through the opening in the removed fuel pump (inside the tank). I believe the epoxy will resist the torque from tightening the bolt, and the bolt should tighten down securely. It would be a tricky repair, but it you're looking to save $. You could always have the paint shop buy you a new tank. Good luck.

[peterbaron]

The bottom line question is ( I know, you not gonna like it):
why did you let paint shop guys handle fuel pump installation/tightening M6 nuts, that only requires small torque of 9 lb/ft
Now, do not know your machinist skills, but a broken tank flange stud can be drill out, careful, just the ring, not through the tank, and there is limited depth space
* grind off sticking out stud to the ring level
* sharp centre punch mark right in the middle of the broken stud - the more perfect you are, the better result you'll get
* for M6 stud, use cobalt or HSS M2 drill bit, to drill out a pilot hole approx. 5-10 mm deep/not through the tank, then M5 final drill bit. Do not use cheep drill bits as it will wreck your job!!
Use masking tape to limit drill bit length/penetration while drilling
* tap M6 thread. A set of 2 taps would be perfect, starter and finishing
* a custom length M6 flange bolt (not a bolt with flat or spring washer) to suit your needs.
When drilling, use WD40 as cutting oil, small/handy drill with slow to moderate speed with 90* angle to the tank's plate.

A few examples:









Other method for less skilful operators is to drill it right through, use M6 flange stud and seal it with JB weld or Loctite for gas tank application.

https://www.loctiteproducts.com/en/produ...pound.html

https://www.jbweld.com/product/waterweld-epoxy-putty

Also check youtube for your convenience, plenty there.
Professional machine or radiator shops might be handy as well.

By reading your posts, I know you have mechanical skills, so good luck in successful repair by either way
Feedback and pics mandatory when completed.

[PowerDubs_imp]

New tank time.

Last thing you need is a 'good enough' repair that seems to work for a year or 2 then leaks again, rusts out, etc.

No way whatsoever I would want a repaired tank compared to a factory built tank.

[Just One More_imp]

I’m sorry to hear this! My fuel pump stopped working due to fine sediment that was in the tank. When I pulled the gas tank off and flipped it over, I found that two of the six mounting studs were completely wrung off. The remaining mounting nuts were so tight on the studs that I’m surprised they didn’t shear when I took them off. I drilled the broken studs out and replaced them with 6mm bolts of the same length. I had to cut small slots in the retainer ring once I punched out the broken studs and bend the outside edges up slightly to accommodate the replacement of the studs. Once the bolts were inserted and the tabs bent back into place, I used some JB Weld to finish up. I ended up replacing the fuel pump assembly then with a new gasket and retainer, put things back together. 9 lb/ft on the nuts! I didn’t have a clue about what I was doing…save a bit of common sense. I want to encourage you to tackle your issue but try not to get in a hurry. A repair beats laying out all that cash for a new tank. I must say that my first thought was to replace my tank. I’m glad that I didn’t and I’ve had no further issue!

[GoldOxide_imp]

Similar to [url=http://cb1100forum.com/forum/member.php?action=profile&uid=3454]PB and JOM, I would at least try to repair it. There is nothing to lose, and something maybe to learn.

I repaired a motorcycle fuel tank before and I was soooo unexcited. But with patience and common sense, it worked out permanently.

[LakeWylieJoe_imp]

Well crap. That's frustrating as hell. Whatever you do, I'd get the paint shop to pay for it.

[pekingduck]

The tank is repairable, with the right skills of a good experienced welder/fabricator.

First, any residual fuel vapors need to be neutralized or evacuated with compressed air before any drilling/grinding or welding.

The mounting ring is 2mm thick. It was drilled, stamped, and six 6mm "bolts" dropped into holes and tack welded in place. The mounting ring is then spot welded in place in 6 locations onto the bottom of the tank.

If you drill through the stud, you are basically drilling through the bolt's head, about 2.5-3mm thickness, not the mounting flange itself. If you were able to thread it, using a bottoming tap, you would have at most 2-3 threads catching.

The raised portion of the mounting ring needs to be perfectly flat and even to let the gasket seal properly, so remember not to apply much force with the centerpunch or the drill bit.



I would recommend very carefully cutting out a section of the flange with a cutting wheel so you can put the piece in a vise and properly replace the bolt and weld it in, before welding the section back into rest of the flange. That ensures it is flush and level.

[tod.branko_imp]

Thank you all for the suggestions. My mechanical skills are decent but machining and welding skills are practically none and I don't have access to a welder. I have made a formal complaint with the body shop, they've asked me to drop the tank off, they will either fix it or get me a new tank if that fails. It's unfortunate, but I guess these things happen, I was very eager to get on the bike and go ride, it has been too long. At least I'm happy with the new look, still contemplating the proper exhaust and grab rails

'14 CB1100 STD 5 speed

[Tev62]

Just a reminder to those thinking of using JB Weld. If it has anything to do with fuel make sure you use the "MarineWeld" version which is petroleum resistant.