Broken top cover bolt question

I went to replace my top cover gasket and cam end plugs because of an oil leak on my 82 kz1000. When removing the top cover the front center most bolt was extremely tight backing out. Thought I was being gentle, but the bolt snapped when backing it out. There is enough bolt left showing to grab with vice grips, but after soaking in PB blaster it still won’t budge. I had to ride it home so I put the top cover back on minus that one bolt got home and to my surprise there was no oil leak from that area. The other bolts must have created enough seal. I know I’ll likely need to drill it out, but I don’t trust myself to do that without making things worse. Anyone in Alabama that you’d recommend for that type of job? I’m in the Birmingham area. Other question is would you park the bike? I’m tempted to just keep riding it in the meantime since the other top cover bolts seem to be holding a good seal. Would you ride the bike like this? Open to any advice. Thanks!

If it ain't leaking then it won't hurt to ride it - do you have the resources to weld a nut to the broken bolt then cycle heat and penetrating fluid  on the area around the bolt before trying to undo

I hear ya and no unfortunately I do not

   There's a potion of 1/2  & 1/2 transmission fluid and acetone for we swear by for threads.  We call it Magical Mystery Fluid (MMF).  Found the recipe in a machinist's magazine many years ago.

   If we understand the situation, the bolt is directly below the center frame rail?.  That's gonna block drill access.

   You indicate enough exposed fastener to clamp with a tool.  Engineer produces a variety of plier tools purpose-made for this job.  The right one can grip as well or better than common vise grips.  There's many sizes and designs. One example:
 


    If a removal attempt is planned, keep the exposed fastener wet by introducing a few drops of MMF down the empty valve cover bolt hole every few days for a month or more.  If there's any way to strike the end of the bolt vertically with mild hammer blows using a punch down the hole, the shock can help break the grip of corrosion that may be present.  Heat will be your friend.   Ride as often as desired to heat cycle the area.  Wet it often between rides.

  When ready to attempt removal, ride to heat, then use a hot air gun aimed closely at the area to keep it very hot while removing the valve cover.  When the broken bolt is accessible with tools, rock it back & forth gently.  Keep it hot, wet & take your time.

Good Ridin'
slmjim & Z1BEBE

If there is enough protruding to get a bite with one of these they are very effective (grip like whore on your wallet)

I used one of these to remove a rounded cap head screw that had minimum access.
www.amazon.com.be/-/en/Extractor-Left-Ha...emoval/dp/B0BNDGXQ2H

Honestly.. I wouldn't be too concerned about it. The  J engines, like Yours Did have a camchain slider up top on cam cover but bolt pattern clamping the cover was triangular clamped. That missing center most missing/snapped M6 isn't going to cause you much havoc. You can purchase tools to remove it but you're only going to break it further/flush. I've advocated using an impact wrench on All this old machinery. Trying with a socket and rachet is TOO slow and only "twists" the shaft of bolts. You want snappy percussion FAST removal!! You've already witnessed, no leaking. Leave it be.      

I was going to suggest TIG welding a nut onto the remaining stub, but I see that Wookie beat me to the punch!
Good luck!

Mike

Thanks guys this is all great advise. I think I’ll be able to get it out with the correct tools, but decided to just leave it be for now and address it later since no oil is leaking from the cover. Replacing the cam end plugs and gasket fixed my original issue which was a top cover leak so I’ll take that win. No more oil dripping down the cooling fins as in the past. Been riding it back and forth to work with no issues. Gonna keep an eye on it and make this a winter project. Here’s a pic of what I’m working with. As you can see not much to grab onto with vise grips. Side note check out that scratch on the outside cam lobe. It’s got me wondering what could have caused that. Any thoughts?

  Not entirely familiar with that head.  If the bolt hole is open at the bottom, spray whatever thread potion up into the hole to soak the threads from underneath.

Good Ridin'
slmjim & Z1BEBE

Good advice, it is a through hole

Whoops i goofed! Thought you were talking about the inner most in line with spark plugs. Your situation is different. Quite hard to access as you've found i'm sure, from the top. Try this. Use a fair amount/length of 1/4" tubing over what remains. Fill the length with something like Kroll or some equivalent. Let it sit for a few days.. It'll wick down around threads. Then using a decent set of sharp vice grips, grab that arrogant remnant and see if you can wrench it back and forth. You can use a propane source to heat immediate area but Golly be careful!! Aromatics can make this all moot and ablaze your domain!!