Broken bolt

[Strikezone]

Earlier today I was replacing the zincs on my Yamaha OX66 and sheared the heads off two of the bolts. This anode is the one near the tilt and trim unit. The anode had gotten really crusty and the bolt threads on the two I was able to back all the way out were really salty and dirty.

There's about ½" of the bolt sticking out of the bracket assembly. I didn't try to remove these until I got some opinions about the best way to attempt this.

Has this happened to anyone else and how did you take care of these broken bolts?

 

[richie rich]

yeah...the heads of the bolts actually broke off, but only 90% of it...a thin layer of bolt head was left but would not handle the torque.....had to heat it up with a torch real well....spray with liquid wrench type penetrant while hot and then let it cool for about 20-30 minutes.......then get a really good solid grip with vise grips and slowly rock back and forth a little at a time....it will break free just a hair, but then continue twisting left and right until the bolt gets more loose each time....there is still a chance breaking...but it worked on many a bolt for me...

 

[Marty grady 272]

I had the same problem. I was able to cut the zinc anode off with a hack saw and once it was split I used a hammer and a small chisel to spread and clear the zink away from the bolt shaft. I then used an penetrating spray and visegrips to rock the remanider of the bolt out. On my twin powered I had to remove 5 bolts this way. When installing the new anodes I then used a flat washer and a lock washer and anti seize. If the bolt head now breaks off there should be enough bolt legnth left to grab.

 

[Capt Bill]

Two of mine broke off last year, but there was a half inch of stud sticking out. I sprayed them with PB Blaster (auto-parts stores carry it), and let it soak for a half hour. They came right out with a pair of very small vice-grips.

 

[NOTHING ELSE MATTERS]

Blow torch, penetrating oil and vise grips. Good luck.

 

[Strikezone]

Sounds like the concensus is to spray some penetrating oil and work it with a vise grip. This was my first thought also, I just wasn't sure if I could loosen the bolt without further shearing.

I'll be greasing the new bolts with some water resistant grease before reassembling much like the bolts in the lower unit.

Thanks for all the replies.

 

[seasick]

Use antisieze on the bolts and they will be fine. On the bolt that the ground strap attaches, avoide antisieze or greese under the head or on the washer. You need a good ground for the anode to work correctly.

 

[Strikezone]

We by after work today and sprayed the broken bolt studs with a generous amount of WD40. Let it seep in a minute or so and was able to easily back out the rest of the bolt. It seems that the corrosion that caused the bolt to shear was where the zinc was in contact with the bolt.

Everything is back together and ready to be splashed.

 

[TonyUSMC]

I cut the end of the bolt off and used a 1/8th inch thick cutting wheel on an air powered cutting tool and used some tri-flow lube and a large flat head screw driver to back it out. then again the bolts i was backing out wernt too far gone; they had some strength left.

 

[JUST-IN-TIME]

you need a gas torch

i always hit bolts up that are on the engine with PB or the torch first