How to Extract a Broken Bolt from a Motorcycle Engine Block

A motorcycle.
  • 1-3 hours
  • Intermediate
  • 25-50
What You'll Need
WD40
Mole/vice grips
Stud removal tool
Drill with reverse rotation
Several left hand drill bits
Bolt extractor
Number of mechanic
What You'll Need
WD40
Mole/vice grips
Stud removal tool
Drill with reverse rotation
Several left hand drill bits
Bolt extractor
Number of mechanic

If there is a broken bolt that is lodged into your motorcycle engine block, then you will find that it can be difficult to extract it. However, there are a few different things that you can do to try to get rid of the bolt without doing damage to any of the surrounding areas or causing the bolt to become further lodged into the engine block. You will simply need to keep a few things in mind and work slowly and carefully.

Step 1 - Use WD-40

Typically, whenever this happens, it is because the head has broken off and the actual shaft of the bolt is sticking out of the block. There is usually a reason why the bolt broke in the first place. It is a good idea to go ahead and spray WD-40 or something similar in the area to make it easier on yourself. Once you have done this you are ready to move on to the next steps.

Step 2 - Use Grips

With the grips, you will need to get a tight hold on the part of the shaft that is exposed. You will need to move it around, forward and backward, to loosen it as much as possible. Once you have got it to move around, you should be able to gently persuade it out of the area that it is stuck in. Once you have done this, you are finished.

Step 3 - Drill

If the shaft is not exposed and is broken flush to the surface, then you may need to get a drill to go down to the center. Use your stud removal tool to get it out. If you are unable to do it with this tool, then you will more than likely have to drill down to your bolt using a drill. You will gradually use bigger drill bits as you go. Make sure that you use a left hand bit as it possibly could hang the bolt and unscrew it. You will do this until the old bolt has collapsed and fallen out. Once this has happened, you will need to get a blind tap down onto the hole so that you can clean the thread out completely.

Step 4 - Use a Bolt Extractor

It is also worth trying to use a bolt extractor for this task. You will be able to find them at most auto parts stores as well as any hardware store. This is something that will only work if the shaft is exposed. If it is not, then you will need to drill it as previously mentioned. If you do not feel comfortable doing this, then simply take it to a mechanic that will be able to do this task for you. They will more than likely weld a nut to the stuck bolt and remove it for you. If at any time you begin to feel as though you are in over your head, then you should immediately contact a mechanic to prevent further damage.