This explanation is followed by a question or several...<br />Ran into this a few years ago on a 70's model Johnson that had never been in salt water, and the boat was stored inside (taken care of).<br /><br />Ran into it again yesterday on a 91 Yamaha.<br />Trying to remove the powerhead and the heads snapped off of a few bolts. They were seized inside the holes. Threads were not seized.<br /><br />Started out with a real torch, heated several times. Shocked the bolts with a hammer. Heated the housing a few times, then the bolts. Cooled the "bolts" with drop of water. Rocked em back and forth by hand using "feel" to stop and start. Just typical of trying to keep from breaking a bolt that was suspected of being seized. <br />It worked on most of them, but, not on all.<br /><br />Ended up making a decision as to sacrifice the spacer between the exhaust can and the powerhead to keep from ruining the powerhead.<br /><br />I took a cutoff wheel and cut into this spacer about one inch below the powerhead. Cutting through the bolts. Figured it would be easier to pry out one inch of corrosion than 5 inches.<br /><br />This worked at the expense of that spacer, and....later the exhaust housing and the tuner.<br /><br />All of this was taken in stride and my GREATEST fear never came to be. My greatest fear was that the bolts would be seized in the threads and would break off flush with the powerhead. I would then be drilling, tapping, helicoil. The worst of which would have been drilling a hole in a stainless steel bolt.<br /><br />Anyway, all this got me to thinking....<br />Surely a person or company that rebuilds powerheads has something figured out to make this job easier. Maybe soaking the engine in some sort of chemical? Soaking it in a vibrating solution tank (much like what a jeweler uses to clean jewelry...except larger)??<br /><br />It's not so much a question about how to get bolts out for the average person. It's just that boat motors probably have an extremely high percentage of being turned into scrap due to broken bolts (cost of removal-vs-cost of replacement).<br /><br />It's more of a question of "does the rebuild industry have a better way to handle this inevitable problem"?<br /><br />Me, learned my lesson now. If I'm using it, I'll be taking it apart once every couple of years just to prevent this. Looks like my routing maintenance is a "big job" every so often.