Stuck bolt that spins freely, in awkward spot

[larrynyc]

On my stock '75 XS650, a bolt is stuck but spinning freely. It's the lower bolt that the left airbox mounts to the battery box. This means I cannot remove the left airbox, which makes removing the left carb nearly impossible.

The thing is, that spot is very awkward. The rear of the bolt isn't touching anything. I can't tell if the bolt is stripped or the hole itself is the issue.

The bolt (and airbox) is stuck where the "A" is shown. "B" is a small gap, where I can barely fit just the tip of my pinky finger in there to feel the rear of the bolt, and there seems to be a small nut welded in that little spot (I can't really see). That gap is super small, you can't really get any tools to fit in there. The bolt is all the way in, and spins freely in either direction and doesn't "catch" on anything. It seems to be in this situation from tightening it way too tight the last time I put the airbox on.

How do I go about removing this bolt? Thanks in advance

 

[retiredgentleman]

Use a slot screwdriver or similar tool. Put the blade behind the head of the bolt, and apply some pressure, so that the force is pushing the bolt outwards. While doing that, use a socket to unscrew the bolt.

Once the bolt is out, use the next larger size tap, to tap a new thread.

 

[weekendrider]

Is the nut spinning also?

 

[grizld1]

Good call as usual, rg; that's a 6 mm. bolt, so 1/4x20 tap and fastener will get it done without much loss of material.

 

[Brassneck]

If you can't get anything back there to put pressure on the bolt, as suggested...then you may be able to get a vice-grip on the head, and pull back as you turn the bolt...ultimately you are trying to get the threads to re-set into that fixed nut.

How much of the bolt is in there vs. on the front side? Perhaps cutting off the head, and pushing it through could work, if the remaining bolt is small enough to slide out....I am guessing not, but it's an idea.

If that fails, you could try drilling it out... but I would do that as a last resort, as it can get messy and a total pain in the ass since the bolt spins freely.

 

[gggGary]

Dremel the head off? Acid from a disconnected overflow tube is what usually fuggles that bolt, I've been there on that very bolt.

 

[larrynyc]

The hidden nut behind the bolt doesn't spin, it's a welded part attached to the battery box. I tried four different methods to try to get the bolt out --

Flathead screwdriver under the head of the bolt:

I had to really dig to get it in there, the screwdriver is under the washer. I pried the bolt outward as I used a 10mm socket to unscrew it. It did not work, the bolt just kept spinning counterclockwise and did not "catch" on anything.

Flathead screwdriver *behind* the bolt:

The screwdriver barely fit, but I got it in there. I pried the bolt outward with a good amount of pressure as I used the socket to unscrew it. Again, the bolt just spun freely and didn't catch on anything.

Between the boxes:

I wedged the screwdriver between the air box and battery box, using a similar method as before. Still didn't work.

Vise grip:

I clamped down tight and pulled with all my might, as I slowly rotated it counterclockwise. It will not unscrew. And it will not pull out. But the bolt still spins around freely. So freely I can use my fingers to spin it.

It looks like I will have to drill it. I assume I should hold the bolt in place with the vise grip as I drill. Is there a special drill bit I should use for this scenario? Thanks

 

[Brassneck]

Is there any way to get a little saw in there and cut the bolt off from the back? Perhaps a jigsaw w/metal blade, or hand-held? Holding the nut with the vice-grips and cut away may be easier than drilling it out... once the bolt is cut (as close to the welded on rear nut as possible) it may pull out.

 

[fredintoon]

- - - It looks like I will have to drill it. I assume I should hold the bolt in place with the vise grip as I drill. Is there a special drill bit I should use for this scenario? Thanks

Hi larry,
drilling the head off will work better if you hold a box-end wrench on the bolt head instead of a vise-grip.
First, make an effin' great centerpunch mark as near the center of the head as you can eyeball it.
Then drill mebbe 3/8" deep with a 1/8" drill bit.
Then switch to a 5/16" drill bit (it's sufficiently larger than 6mm that drilling off centered a little won't matter) and drill away until the head falls off.
New, sharp, good quality HSS drill bits and a proper cutting fluid make the job easier.
Reserve buying the expensive Cobalt steel drill bits for drilling your XS650's brake disks, which are made from the toughest stainless steel I've ever worked on.