Sheared Bolts on the starter motor

strikeback03

Seaman Apprentice
Joined
Jun 13, 2007
Messages
41
Re: Sheared Bolts on the starter motor

Where did they shear off? Can try grabbing them with Vise-Grips, or drilling in the end and using one of the bolt-remover sets
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Sheared Bolts on the starter motor

starter motor on what. where did they break?
 

bds85466

Petty Officer 1st Class
Joined
Jun 11, 2007
Messages
375
Re: Sheared Bolts on the starter motor

It's on a 72 125hp Johnson. The bolts which sheared are those that connect the starter motor to the casing of the boat motor. They came off at the heads, leaving zero real estate to grab.
 

bds85466

Petty Officer 1st Class
Joined
Jun 11, 2007
Messages
375
Re: Sheared Bolts on the starter motor

I'm assuming I could get some ez outs/bolt extractors. How about resetting the bolts? Should I use lock washers maybe?
 

R.Johnson

Rear Admiral
Joined
Sep 24, 2003
Messages
4,446
Re: Sheared Bolts on the starter motor

You have stainless steel bolts' broke off in an aluminum block, you are in for one sweet time. First, unless you want to make matters' worse, you will need some outside help. Have a drill bushing made that will fit the mounting bracket mounting hole. Bolt the starter back in place with the bolt that is left. Use a left hand drill to drill out the broken bolt, going clear through the bolt if need be. Many time's this will unscrew the broken bolt. If you try the drill, easy-out trick, you can do the Roman General finish! fall on your sword.
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: Sheared Bolts on the starter motor

If you find a good machine shop, you will have a much better chance for a happy ending to this problem. If you make a mistake, the starter will not engage the flywheel properly.
 

bds85466

Petty Officer 1st Class
Joined
Jun 11, 2007
Messages
375
Re: Sheared Bolts on the starter motor

Well, thanks for all the confidence builders, guys...

Last night I got both bolts out successfully by drilling through them and using bolt extractor bits. Quite painless actually. The only issue (and time consuming thing) that I ran into was the orientation of one of the bolts. In order to get my drill at it perpendicularly, I had to remove the fuel pump and front plate/peripherals of the carb. First thing I did was carefully spray some release agent/penetrant onto the sheared bolts to make them as loose as possible. I used some gear oil as drilling lube with hardened steel bits...worked like a charm. I also used a sharp carbide point as a tap for a pilot hole so the bit wouldn't wander when I first started drilling. Didn't need to go in more than two tenths of an inch to get the bolt extractor to work. Twisted them both out with little resistance (hands/tap wrench). I replaced the bolts using lock washers. Took me about 2 hours and cost much less than the machine shop.

BTW R Johnson, I find it tough to believe that the block is made of aluminum unless it is an alloy. Aren't most blocks made of cast iron?
 

R.Johnson

Rear Admiral
Joined
Sep 24, 2003
Messages
4,446
Re: Sheared Bolts on the starter motor

You make it sound so easy, wish I would have thought of that.
 
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