Captured nut in tank problem

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Captured nut in tank problem

Postby bic_bicknell » Fri Jun 30, 2017 12:53 pm

Since 2007 I have experienced the loss of a mounting point for my tank spoilers at about the rate of one every two years.

As many of you know the spoilers are attached to the tank with bolts that screw into nuts moulded into the tank. This is fine until the screw corrodes into the nut or is overtightened resulting in the nut starting to turn within the plastic. On the bottom points this can be resolved by cutting the bolt with a hacksaw and doing without the bolt. Sometimes you can get lucky and somehow get the bolt out and then inject some superglue or resin around the bolt to secure it - at least well enough for it to work OK (if you remember never to over tighten it!!).

But now I have one of the top allen bolts stuck in a revolving nut. This is the really prominent one on the top side of the tank and you can't get a saw behind to cut the bolt. I have to fine a way to resolve this because there's no way to top up the water expansion tank or fill oil without removing this spoiler.

Anyone have any tips for me before I decide I have no alternative but to drill the bastard out and hope I don't damage the tank in the process? Of course if I do this it won't give me a solution for how to hold the spoiler on again.

KTM should accept they made a pretty shit design decision here. ;(
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Re: Captured nut in tank problem

Postby DribbleDuke » Fri Jun 30, 2017 5:53 pm

This might sound nuthouse but can you leave that connection in place and swivel the panel up for required maintenance? You may have to squirm the front black filler piece out of the way and possibly leave it off after being able to reach the inner screw for removal. this is a short term fix that will ultimately lead to the drill motor in your hand in the future. I think you answered your own question. Drill...

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Re: Captured nut in tank problem

Postby No. 47 » Fri Jun 30, 2017 11:00 pm

Aye, can't think of any way other than drilling - have spare tank if you need short term loan whilst you get yours sorted.
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Re: Captured nut in tank problem

Postby jmann » Sat Jul 01, 2017 12:40 am

Comrade Bic: Can you thread the original at all? If you can and could get almost to the point where the nut is filled with the bolt then you might be able to effect the following repair - drill the bolt with a hole as big as you can get whilst maintaining the thread, then inject resin Etc. through the hole to fill the nut-turning space. Allow to harden and remove the drilled bolt or leave in place. To thread the bolt you obviously need luck with the original threads (turn fast maybe with a drill) then pull outwards to use a bit of friction to get some more thread.

Sometimes a fast spin in a drill can get a bolt out - it relies on the inertia of the nut. If you can get the bolt out drilling an injection passage is a lot easier.

Good luck.

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Re: Captured nut in tank problem

Postby SilverBullet » Fri Sep 01, 2017 5:41 am

I put a bit of pressure on the nut to get it out from the tank using a screwdriver to pry it out carefully whilst turning the bolt head. Once it was all out put the nut in a vice and undo the bolt. I then superglue the nut in place and all has been good since. Hope that makes sense.

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Re: Captured nut in tank problem

Postby DougFir » Fri Nov 10, 2017 5:49 pm

Left hand drill bits to the rescue.

4 the next guy.

Lefty bit heats up the trouble fasteners as it is drilling and also adds good vibrations.

Some sort of penetration oil can't hurt.

With luck the bit will catch and spin the screw out.

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