Need advice how to remove broken bolt from engine block

Fikus

Cadet
Joined
Apr 7, 2015
Messages
29
Hi.I have a broken bolt that holds starter,i saw couple videos how to remove it but may be somebody did it already and can advice on what drill bit to use?

Pics attached.Thx!
 

Attachments

  • photo231071.JPG
    photo231071.JPG
    138.1 KB · Views: 1
  • photo231072.JPG
    photo231072.JPG
    275.4 KB · Views: 1

Reel Kahuna

Petty Officer 1st Class
Joined
Apr 3, 2010
Messages
271
The only thing you can do is use a "center punch" and try your best to "prick" the center of the bolt. Then start with a 1/8" drill and drill thru the bolt. Once you've gone thru the bolt, then use a 3/16" or 1/4" diameter drill to enlarge the hole. Repeat increasing the drill diameter until you can remove the broken bolt.
No easy job but the only way to do it. Best of luck.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,464
but may be somebody did it already and can advice on what drill bit to use?

Ayuh,.... Welcome Aboard,.... A Very sharp one,......

I've had very good luck usin' a left-handed bit to turn the broken piece out,....

Step #1, is pull the motor for access to it,....
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,296
I second the left handed drill bit and removing the motor.

however I have also had luck when there is about 1/16" or more of the bolt sticking out past the block by simply welding a washer on the bolt, then welding a nut on the washer
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,092
The best way is to pull the motor and put it in a stand upside down.better visability, better performance, much better results
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,585
WOW, a bad place to try and remove a stuck broken off bolt. If there is room, and I can't really see if there is in the pictures, try using a right angle drill with a left or right hand bits. And increase the bit size until you get it out. Usually when you get really close to the threaded section, you can fold the metal towards the center and remove it. The absolute best option is to remove the engine and have the best access to the issue. But that involves a lot more work if you are up to it... JMHO!
 

Rick Stephens

Admiral
Joined
Aug 13, 2013
Messages
6,118
Like Scott, I have usually gone for welding a nut onto broken bolts. The heating of the broken off stub also expands it and when it cools it is looser and easier to turn. Have done this on literally many hundreds of broken bolts and studs on heavy equipment and farm equipment. Left hand drills work if the bolt is easy to turn.

Rick
 

Silver Eagle

Master Chief Petty Officer
Joined
Mar 16, 2010
Messages
852
With my luck, I'd screw it up.I don't weld.So to be safe I'd find a boat shop locally and have them do it. Cheap is not always the best way.
 

Soder99

Cadet
Joined
Dec 19, 2009
Messages
24
No Title

I had a bolt break off in my wakeboard tower and I used a bolt removal tool like the attached picture. Drill a smaller hole, put in the tool and lefty loosey out it comes. You might be able to do this without pulling the engine if you can get a drill or right angle drill in there like suggested by gm280.

As always, spray some penetrator in there to loosen any rust.
 

Attachments

  • photo231124.jpg
    photo231124.jpg
    12.7 KB · Views: 0

Rick Stephens

Admiral
Joined
Aug 13, 2013
Messages
6,118
Other than the motor pull, there is nothing really about a broken bolt removal that is a boat shop job. Any competent mechanic is going to be able to do this. If you can pull a motor you can save a bundle.
 

Fikus

Cadet
Joined
Apr 7, 2015
Messages
29
Thx for the answers! Will try tomorrow to drill it out and just put bolt with a nut after, really dont want to pull the motor out :)
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,464
and just put bolt with a nut after,

Huh,..??..?? The starter has to use Starter Bolts, they're quite Special, 'n No nut, the threads are in the block,....

No other way to do it,....
 

Buster_boy

Petty Officer 2nd Class
Joined
Aug 9, 2015
Messages
178
Left handed drill bit. Trust us they work. Hard to find so you may have to buy online. Granger Sells them.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,296
Left handed drill bit. Trust us they work. Hard to find so you may have to buy online. Granger Sells them.

the only way a bolt and nut are going to work is if your bolt is 22" long and goes thru the one piston and thru the head to come out near the valve cover. As Bondo stated, "Aint gonna work"

This is a case where there are no shortcuts.

your time typing on this thread alone has almost been more time than it would have taken to pull the motor. 1/2-3/4 hour to pull drive, 1/2-3/4 hour to have motor out.
 

Fikus

Cadet
Joined
Apr 7, 2015
Messages
29
No Title

All done!first drilled a hole with 1/8 after with a bigger one,the bigger one locked inside the hole and unscrewed the broken bolt :)
 

Attachments

  • photo231200.JPG
    photo231200.JPG
    152.2 KB · Views: 1
  • photo231201.JPG
    photo231201.JPG
    176 KB · Views: 1
  • photo231202.JPG
    photo231202.JPG
    209.3 KB · Views: 1

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,585
Bravo Fikus, Bravo... You did a great job with that broken bolt. I can tell you they are a lot harder some times. But take it as a job well done... Happy boating... :thumb:
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,464
Ayuh,.... Congratulations,..... You now qualify as a full fledged "Mechanic",...... ;)

Last one I did was a 3.0l in a boat tied to the dock, on an island,.... rockin', 'n rollin',....

I forgot to bring my mirror, luckily, the lady of the family of course had one in her purse,... Saved the day,....
The 1st second or two of my blind drillin' with a battery right-angle drill, 'n left-handed drill bits,.....
Was OFF the mark, by a Mile,.... well, 1/8" anyways, right on the edge,....
With the mirror, I repositioned to center, pulled the trigger, 'n the stub just rolled right out, as soon as it "Bit",...

Earned my keep that day, 'n left the island a Hero,.... :D
I told Mom, she was the Real Hero,.... :)
 

Fikus

Cadet
Joined
Apr 7, 2015
Messages
29
Thx guys! my question is right now if i need to order special starter bolts or i can use the regular ones(i bought regular ones)?
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,464
Thx guys! my question is right now if i need to order special starter bolts or i can use the regular ones(i bought regular ones)?

Ayuh,.... See post # 12,.....
 
Top