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Help!! Broke the head of my hex screw that screws in the gas tank

1K views 9 replies 7 participants last post by  gino33 
#1 ·
I just bought this bike a few weeks ago... I ordered a USB charger and went to install it today. I went to remove the tank and the screw was very tight. I added some torque (with my hands) and BANG my hex screw head ended up in my socket. Any advice?

See the pics below:
Automotive design Motor vehicle Steering part Automotive exterior Electrical wiring
Rim Automotive design Gas Carbon Electric blue
 
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#3 · (Edited)
Use a center punch to keep the drill bit from walking. Select a drill bit for whatever size Allen wrench you want to use. Pick one that is at least 3mm. Now drop down 3 sizes on the drill bit and start your hole and increase the bit size until it is close to the Allen wrench size. You do not want the Allen wrench to slide into the hole. Basically you want the hex points to be slightly larger than the hole.
I'd recommend removing the gas tank so the drill doesn't scratch it and so you don't hit it in the next step. The seat covers most of the area either way but if you're like me... You will know it's hiding under there!

Now use a hammer and keeping the Allen wrench as parallel to the hole as possible, tap the wrench in as far as you can. Then extract. I have used this hundreds of times, unfortunately. If the wrench slips in the hole then try a standard size wrench in the same hole using the same method.

As a last resort, only because of the amount of work to remove everything in the way... That bolt extends below the welded nut. You can remove the battery, relays, fuse box and battery box to get vice grips on the other side. If you go with this method do not try and back the bolt out, continue threading it down and out.
Here's a little advice if you take the tank off. The fuel line is a push lock so squeeze the tabs as you push in then pull apart.
https://www.m109riders.com/forums/showthread.php?t=331865&highlight=Remove+gas+tank
Good luck!
 
#4 ·
I meant to add, there are several reasons I do this. Poseidon suggested easy outs and they do work at times the down side is they usually are not in your tool box when you need them. Also they are often cast pieces which means they have microscopic cracks in them known as porosity. Porosity causes stress risers which leads to them breaking and leads you to throwing things and colorful language. Any decent Allen wrench set is made of tool steel which has a high tensile strength and way less likely to break. If you find the Allen wrench bending enough to make you nervous, step up the size and go at it again.
 
#6 ·
Left Handed Drill Bit

You could also try drilling the hole in the bolt with a left handed drill bit. Use a little WD-40 or simillar and sometimes the broken part will just come out while drilling. Good Luck!
 
#7 ·
Thank you all! Bought some left handed drill bits and going to try the Allen wrench method. I have never earned of the before. I am scared to try the ez outs in fear I escalate the problem. Do you think I need cutting fluid or will good can of penetrating oil due the trick?
 
#8 ·
On the bright side, that bolt just holds the tank in place, no real clamping force other than to keep it from flopping around. If all else fails drill the whole thing out little by little and retap with the same are a little larger bolt. That bolt only needs to be snugged up. I would also apply some heat, who knows if the last owner used loc-tite
 
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