OMC Sterndrive Zinc Anode Problem

[Neckpants]

Hello from the Northeast,

While attempting to replace the small anode on the rear of my engine the bolt that secured it was broken off (Most likley corroded and weakened). My question is:

Is there any way to safely extract this headless bolt?
-The prop spline seems to get in the way of using a drill

-If not-

This Four Winns will be moored in salty/brackish water-Can I get by without having a zinc in this location? I have two others(Transom/forward part of engine)

Boat: 1989 Four Winns 160 Freedom
Engine: 3.0 OMC 4 Cycle 130hp

 

[studdy05]

Re: OMC Sterndrive Zinc Anode Problem

Depends if you leave it in the water a fair amount of time with any current in it.

My first thought?
Zinc is a fairly soft metal. Taking a chisel and gently try to tap around on it to knock the zinc off the anode to where the screw cap that the screw screw screws into is and seeing if I could tap back down through the bottom of the lower unit.

My luck with drilling stainless steel bolts has been poor. Thats the hard way.

 

[DBreskin]

Re: OMC Sterndrive Zinc Anode Problem

I had teh exact same thing happen to me a few weeks ago and haven't fixed it yet. I plan to drill it out by renting a right-angle drill from Home Depot so I can clear the prop shaft.

I wouldn't leave the boat in salt/brackish water for more than a day without the anode in place. The anode was put there for a reason.

 

[full stringer]

Re: OMC Sterndrive Zinc Anode Problem

check your yellow pages for a bolt extraction company that uses a( e g m machine) they are mobile most of the time what the machine does is disentergrate the broken bolt using electrical current down the center of it vaporizing it and then they remove the bits and peices from the threads leaving everything else perfectly untouched i used a company in california called jims tap extract cost me 40 bucks well worth it to me good luck

 

[Neckpants]

Re: OMC Sterndrive Zinc Anode Problem

I appreciate all the great advice!

I wasn't able to find a bolt extraction service in my area after an internet search but if I do I will gladly pay $40 to have them sweat over it.

My plan of attack is use a right angle drill and a screw extraction kit:
1. Using the right angle drill I will drill a "pilot" hole in the broken bolt
2. Tap in the screw extractor
3.Use a T handle to turn the extractor bit counter clockwise to remove the bolt.

-I agree with Studdy that drilling a steel bolt is extremely difficult and potentially could harm the engine.

This will be my weekend project (In addition to some antifoul touch up) so I will update as soon as I have an outcome.

Thanks again...