Is there any way to reconstitute a damaged head gasket bolt hole on the engine block for my Starflite III? I was able to successfully remove all of the head bolts but this one. After several applications of heat/cooling cycles, I thought I had it coming only to discover I was twisting the head off the bolt. I tried to drill out the remaining part of the bolt but the drill slipped off and went down be side the bolt. I finally was able to remove the bolt but am left with a badly distorted mounting hole. I seemed to remember reading about a product that could be put into a damaged hole and then retapped to original specifications, but I can't relocate it on the Internet. I will appreciate any help anyone can provide.
You should be able to repair that with a Heli-Coil kit. Most kits come with a tap, installer and typically a few stainless coiled inserts. The drill size for the special tap will be engraved on the tap.
Once you have drilled and tapped the bolt hole, you wind the stainless insert onto the installation tool, then carefully screw the insert into the threaded hole, until the insert is slightly recessed in the bolt hole. Unscrew the insert tool then using a small screwdriver or other suitable too, break the "tang" on the insert that allowed the tool to drive-in the insert.
As long as you have a fairly intact bolt hole, this will work great.
As I recall, those head bolts are 5/16-18 (NC) and here's a kit on eBay for $17.99 shiipped:
If that's the wrong size, just do a search for the correct-sized bolt. But I don't recall 'em being 3/8", and the only 2 possible sizes for those head bolts would be 5/16" or 3/8".
Be sure to check the head for flatness; if it's warped, the new head gasket will blow out in short order. You can have a machine shop plane it down (i.e. "surfaced"), or do the job yourself on a large enough piece of flat glass (or a flat metal workbench), working the head in an oscillating motion with sandpaper on the glass. If the head is really bad, start with coarse then work up to medium then fine.
When installing the head/gasket, spread a thin coating of Permatex No. 3 Aviation-Type gasket dressing on the head bolts. This will keep them from ever seizing in the head or block. You can pick up a small bottle with the screw-on brush cap at most auto parts stores.
HTH, let us know if you have any questions about this repair or anything else on your outboard..........ed
p.s. On the eBay links, this forum's software parses them, so you'll have to take out the spaces to make 'em work. Or just copy the item # out of the link, and plug that into the eBay search box.