Broken Bolt.I am stuck

So I posted a quick note about this before in my other thread, but I had a valve cover bolt brake off in the head. So I went about trying to remove it. Thinking that it was small enough to use a left handed drill bit. That did not work and not i am un able to find a easy out that will fit in there to remove it. Im starting to thinking that i may have to pull the head bring it to a machine shop or somthing to get it out. So i am stuck with a bolt in the had with a hole in it. This is just not working out for me.

 

You can grind the end off a easy-out to help it fit better. Hopefully the hole is centered in the broken bolt. If it has wandered off center and is hitting the original threads it will be dificult to remove.
Try this;
Soak with penatrating oil for a day or so
Grind the tip off a easy-out to make a good fit.
Heat the area around the bolt with a propane torch and try removing when hot.
Make many attempts before removing the head. You'll get other ideas from members, try them also. If everything fails see if you can bring the whole bike to a machine shop.

 

AirdaleAherns, Not being able to see exactly what you have there leaves me wondering just how to approach a solution. #1, if you can take the other bolts out of the valve cover and get the cover off and then take the broken off stud out. If not then if the stud broke off at the top of the valve cover, maybe take a nut, set if on top of the stud, take a mig welder and weld the nut to the top of the stud, welding on the inside of the nut to the stud. Then use a wrench on the nut to take the stud out. With a picture I would have a better idea for a solution. grunt007, 81' XJ750 Seca, Mi.

 

It broke flush with the head. It was the right out side top corner bolt. So there was ntohing to grab on too.

 

Airdale Aherns,
In my reply to your broken off cylinder bolt, or as I thought it was the Valve cover bolt. If the bolt broke off flush with the cylinder then the suggestion I made could possibly work. You would take a steel (NUT) with the threaded hole in it the size of your cylinder bolt stud. Then when you put the nut on the top of the broken stud, you Mig Weld the inside of the nut (threaded part) to the top of the broken stud. A safer way might be to undersize the nut one size just so that when you mig weld you don't get any of the weld onto the cylinder.
Since the bolt head is now broken off of the stud, there is no longer any pressure on the stud and hopefully you can get it out. The other way as you know is to remove the whole head and cylinder which probably means removing the engine also, not sure on that one as far as how much clearance you have. Either way, hopefully now you get the idea of what I was getting at. A little trick which over the years has gotten me out of a number of jams. Like they say, to ERR is HUMAN! To get out of a mess is SUPERB!! grunt007, 81' Yamaha 750 Seca, Mi.

 

Iy you drilled with a left hand drill, Use a left hand tap and tap it Get some left hand theaded rod what ever size you tapped it. If you have less than 50 percent thread try using jb weld in the threaded part and put the threaded rod in . Let dry over nite. Don't get any jb on the wall just in the threaded hole. Don't stip the thread. put in in just till it bottom and leave it alone.
DON'T BREAK THE TAP ! Do it with cutting oil.

 

Airdale.........here's a suggestion--again just a suggestion, but think about it--

How many miles are on the bike? Fairly high? Why not CONSIDER going ahead and pulling the engine out. Remove the head and take it to a machine shop for extraction. Here's why I say that:

1. If you've drilled a bit off center, they can re-dril ON center, get the stud out and then install a helicoil and you're back in business with the right size hole at the right place.

2. NEXT......while the head is out, pull the valves and lap them and lap the seats. While you have it out and after you have lapped the valves and re-installed them, do your valve shim clearance check if you haven't already. The head would be on your bench and very easy to access. Consider new valve stem seals while you're there.

3. Heck, while you're at this point......pull the jug off and check ring gaps, and hone the cylinders while you're there. If you need to change anything, you're already in the neighborhood.

4. Re-assembling it with a new set of gaskets.........gee, fresh cylinder honing fresh seals, gaskets, fresh valves and seats, shims, etc.......sheesh, it would be like a new engine in your bike.

That's exactly what I'm in the middle of with my Maxim X build.

Again just a thought.....................

Dave F

 

Does anybody know if a heliicoil may be a solution here, if worse comes to worse? I'd try drilling the thing out & try to save the threads. But its a pretty small area there & might be little room for error. Deep Creep & heat for starters, drill pilot hole first, then try a slightly larger left-handed drill bit. Worth a try if the only other option is pulling the head. Anyone? Anyone? Bueller?

 

You don't save the thead with a heli-coil.You use a bigger heli-coil tap then the insert to get the original thread size.

 

:::::: The Golden Rule of Bad Situations ::::::

Don't do anything to make the Bad Situation, ... WORSE.
You have arrived at this point.

The BEST thing to do:
Pull the Head and have ALL the Fastening Points Serviced.

Intakes, Exhausts, Upper-cover and the rest.

A resource I use is the local Technical High School Automotive and Machine Shop Instructors.
They love having a REAL World Situation to work on.

They likely have a (E)lectrical (D)ischarge (M)achine = EDM Machining.
Removal of the Broken Fragment by means of DISINTEGRATING the Fragment without harming the Aluminum.

Depending on the miles and condition of the Head.
a) Threaded Holes restored.
b) Valves Lapped
c) Valve Seals Replaced
d) Valve Guides Knurled

You end up cured.

 

Left handed high speed gun tap 5-6 bucks threaded rod 5 bucks jb weld 5 bucks. 16 bucks total. Machine shop ?120 per hour. How many hours will they suck you for ? Who knows.

 

HOLD ON.

If it's a valve cover hold down bolt, chances are the "stub" that's left in the head isn't frozen or stuck in there, just broken off. (Thank the stop collar for that.) If you didn't overtighten it, a PO probably did, and fractured the screw where the threads meet the collar. It should spin right out.

That being the case, you need a small screw extractor set that includes reverse drill bits. You will probably find that the act of drilling in reverse will unscrew the stub as soon as the drill gets a bite and you won't even get to actually use the extractor.

You might want to invest in a set; I got mine for a master cylinder cover screw and it's come in handy more than a few times: http://www.sears.com/shc/s/p_10153_1260 ... 000P?mv=rr

You shouldn't need to pull the head for such an easily accessible bolt; but don't do anything rash and make it worse.

**and if YOU broke the bolt, get yourself an inch-pound torque wrench***

 

Well I finally had some extra time and was able to drill out the broken bolt and re-tap it. So its slowy coming back together. Maybe in a week or so!

Also a HUGE HUGE THANK YOU TOO wwj750! He sent me a extra bolt and thank you very much!

 

Nice job Airdale.

 

Great !

 

Nice work Dude. Get ahold of me sometime if you wanna go cruise around.