lower unit to exhaust housing bolts twisted off

Jmac870

Seaman
Joined
Apr 13, 2014
Messages
53
Looking for some advice here, removed the lower unit of my 76 johnson 9.9 (10E76G) and in the process 2 of the 6 bolts that hold it on twisted off and are flush with the inside threads so there is no grabbing ahold of them with vice grips. My question is if I were to leave it and just replace the 4 good bolts will I run into any issues? if so how should I go about getting them removed, some sort of machine shop to drill them out and re-tap? Any advice appreciated and thanks in advance.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: lower unit to exhaust housing bolts twisted off

Well, they put six bolts in there for a reason. But if you want to trust your luck with four, that's your privilege. Personally, I'd drill out the broken ones and install Heli-Coils if necessary. BUT.....if you are inexperienced in doing this, you probably will make a bad situation worse. Those stainless steel screws in aluminum are difficult and tricky to drill. I've done a bazillion of them, and still have some fear. Best to have a pro do it.....one that has experience doing it. You might find him at an outboard repair shop, if you have a good one in your area.
 

Jmac870

Seaman
Joined
Apr 13, 2014
Messages
53
Re: lower unit to exhaust housing bolts twisted off

no repair shops with 2 hours of me unfortunately, and yes I am definitely not experiences enough to do this myself. There is a small engine mechanic with a very good reputation not far from me though I may ask if he has any experience with drilling these out. As for the heli-coils I am going to look them up as im not sure what they are.
Thanks for input
 

rothfm

Ensign
Joined
Sep 26, 2006
Messages
915
Re: lower unit to exhaust housing bolts twisted off

Somethimes jobbing it out isnt that expensive.

While I like the challenge at times of removing broken, rusted, stuck stuff...If its important enough there are real pro's available.

I was lucky enough to find a shop 1 town away, that is awsome at removing broken things. I brought him a 90hp block with various broken things, some with easy-outs broken inside bolts. He removed them all for me for $75 bucks including a degreasing bath. Very, very worth it.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: lower unit to exhaust housing bolts twisted off

You best bet is to find a good repair or machine shop.
 
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