how to remove broken exhaust studs?

Re: Headlight and Exhaust Options

I recently acquired an '83 Midnight Maxim (750) and the exhaust is trash. There are 3 exhaust studs broken off and the rest are suspect. Anyone had to deal with these? They are so small in diameter I'm wondering of I can drill them and get an EZ-Out in it. I bought some more headers and will be redoing the entire exhaust and want to get rid of the collector box since it is toast, too. Spinalator has given me some ideas.

 

Re: Headlight and Exhaust Options

Hi RicXJ750M,

Broken exhaust studs are notoriously hard to remove. EZ-Outs will more than likely snap off in the hole - which means you will now have a hardened steel plug in the bolt to try and remove....

If there's enough of the stud left, try giving it a good hit with a suitable punch and hammer, than grab it with vise grips and try to undo. Failing that, you can try heating the stud with Oxy. The stud will glow red before the aluminium on the head and this can be done with the head on the bike. After it cools it should be easier to turn.

Otherwise, you might have to take the head off and get a machinist shop to drill out / helicoil the threads.

Once you get them all out, use an anti-seizing thread treatment on your new studs to make sure they won't break off again.

 

You could try these...

Irwin Bolt Extractors

I have a set, but haven't used them yet. They were not terribly expensive, and do not require drilling, or pose the risk of snapping off in a hole. Others have sworn by them. I was planning to use them to get the rusty allen bolts out of my turbo housing when the left side muffler finally becomes unusable.

 

If you go the route of having a machinist machine the busted studs out, go ahead and go up one mm in dia from a 4 mm stud to a 5 mm stud. Then they will not break as easily
Sean

 

Thanks for the info...will check into those Irwin Bolt Extractors. Will post how I come out.

 

DO NOT! I REPEAT -- DO NOT!!! TRY TO USE ANY SORT OF EXTRACTOR ON THESE BOLTS!!! IT WILL BREAK OFF!!

I can inform you from EXPENSIVE experience that it is NOT worth it to even try! I had several of the intake bolts snap off when I replaced the carb intake boots. I attempted to use an extractor, but broke it off. I then brought it to a machine shop, where I was quoted $175 to drill and Helicoil the 5 holes, PLUS $100 to have the extractor burned out with a laser.

The problem is the bolts/studs are very small, so the extractor is going to be even smaller. The bolts/studs are fused to the head by galvanic oxidation, which is like Krazy glue. It does not let go.

Also, be sure to budget about $125 for the top-end gasket set (valve cover, head, and timing chain tunnel), because the old ones can not be reused after you take the head off.

-Matt

 

I sympathize, Taz. Had three of those intake bolts snap off on my Seca. Pushed it down the block to an independent auto garage. After extracting what was left of the three bolts and installing one helicoil, I had to leave $177 behind

It's one of those nasty things about owning old bikes... can't do much about it if it happens, just breath deeply and reach even deeper into your wallet.

GG

 

OK..tis expensive to get a shop to take them out. Anyone tried drilling and tapping them at home?

 

DO NOT! I REPEAT -- DO NOT!!! TRY TO USE ANY SORT OF EXTRACTOR ON THESE BOLTS!!! IT WILL BREAK OFF!!

The problem is the bolts/studs are very small, so the extractor is going to be even smaller. The bolts/studs are fused to the head by galvanic oxidation, which is like Krazy glue. It does not let go.

If you look at the pictures of the extractors in question, you will notice that they do not require drilling like an Easy-Out (an oxymoron if ever there was one). They have a left hand spiral flute that goes over the remnants of the bolt in question, and turns them out like a regular bolt head. The worst that can happen is that the bolt rounds off, or snaps off at the head, at which point, you are no worse off than when you started. Ideally, I'd like to be able to pass a high current electrical load through a bolt and heat it up before I try to break it free.

 

Got the message in the first post...My question was: Has anyone tried drilling (not for an extractor) the bolt out and re-tapping the hole themselves and not taking it to a shop? Seems to me, if you use a carbide bit or better, the broken off stud can be drilled out, possibly drilled to a larger size and then tapped for metric or standard threads. Any thoughts?

 

Actually, I was trying to quote the other post, sorry. Drilling the hole out is a hit or miss affair. I have done it many times at work with mixed results. You need a very sharp bit, preferably a cobalt or carbide bit, and very good aim to keep it from wandering to one side. One other thing I didn't suggest was to use left handed drill bits to remove the stud. You can get them fairly easily from a good machine shop supplier. On another board I visit, dedicated to restoring old machinery, they swear by them. They often have to get out broken studs from machinery that has been lying fallow out in the elements for decades at a time. The trick is that as the bolt gets thinner and thinner, it gets easier to turn (with the help of lots of penetrating oil of course, which can be applied down through the hole). The counterclockwise motion of the drill bit tends to walk out the broken bolt on its own once it gets thin enough.

 

If you are going to try to drill and tap them out yourself, you should try to fabricate yourself a guide. You want to make it sit on the hole at the same angle as the bolt you are trying to drill out and measure the depth to wich you need to drill into the head.. the guide should be small enough to hold your drill bit firmly and possibly bolt on to allow a solid foundation....Any local machine shop can build one for you if you are unsure of your own abilities. Without it, you will more than likely drill into the good material and prevent a helicoil from having the proper strength.

 

Thanks for the suggestions...will keep my progress posted in case someone else has the same problem and doesn't want to spend big bucks to fix it.

 

My apologies.. I didnt bother to check the link for those Irwin extractors.. I've seen those at Home Depot, and they do look somewhat useful.. However, if the bolt snapped off flush (like mine did), they wouldnt do much good..

If you're going to attempt to drill them yourself, I have some suggestions..

- Use a drill press. Don't attempt to use a hand drill. If you are going to try left-handed bits, you need to use a reversable drill press.

- Make sure the press table is tightly secured and perfectly level on all angles.

- Make sure the bit is perfectly centered on the bolt to be drilled. If it is offset, the spacing won't match the flanges.

- Clamp the head onto the table, making sure IT is perfectly level.

- DO NOT GO TOO DEEP! I believe the holes are 3/8" deep. Use the depth stop on the press - that's what it's for.

- You will need a bottoming tap to finish off the threads in the hole. The tap that comes in the basic kit is a standard tapered tap, which will not cut threads into the bottom third of the hole. You will need this whether you are using Helicoils or direct threads.

Good luck
Matt

 

i know it might be a little late, but just as general knowledge, a trick i learned while in an engines class at my school, is that to remove a stuck bolt, you can use a torch to heat the bolt and the surrounding thread, then using a special material (i cant remember what it was called, and will try to look it up int eh book when i get home) you cool the bolt. then since the thread is hot and the bolt is cool there is more clearance allowing for the bolt to turn freely.

 

Just snapped off an intake manifold bolt myself last night. I am sick about it. There is no way heating and cooling helps because of the chemical action between the two disimiliar metals. I will sell this 1982 Yamaha Maxim XJ750 with 22,000 miles on it to anyone who wants to tackle this job for $500 cash. Pick up in Marshall, MI just off I-94. Call Steve @ 269-781-7788 or email: stevesearles@hotmail.com I have too many other projects to tackle this one. My loss is your gain!

 

UPDATE: Just received some titanium left-hand drill bits. Will be trying those--don't want to break an extractor of in the bolt.

 

I don't know about you folks but I have broken off taps and easy-outs in blocks before and the safest way I know of to remove this nightmare it to suck it up and go have the bloody thing TIG'ed out. The heat from the gun helps loosen it up and the results are excelent too. No errant holes to have to deal with. Small price to pay when you need all the metal on the head you can keep. Fella just TIG's a small piece of steel to the ruddy stud and out it comes (usually with the force of your hand). After the stud is removed, replace it and don't forget the antiseeze or you'll be right back where you started in a few years. Good luck.

 

Been awhile, but here's an update on my broken exhaust studs. After I had all the pieces/parts, I was wanting to get the job finished and forgot to take pictures. Bought some titanium left-hand drill bits off eBay. Made sure all broken bolts flush with head by using cut-off wheel in a dremel. Center punched the broken studs. Could not locate the right size metric helicolils, so drilled out old studs with 15/64 left-hand bit. Then drilled 3/8" deep holes with 17/64 standard HSS bit. Tapped holes with 1/4-20 bottom tap. Installed 1/4-20 helicoils. Installed headers and exhaust gaskets (got from eBay) using 1/4-20 stainless hex-head bolts and plenty of antisieze compound. Took about 1.5 hours from start to finish. Did not use a guide or jig, just made sure I drilled at the same angle as the good studs. Have to make sure you watch the angle when drilling those closest to the frame--the bit just about touches the frame tube. Now all I have to do is figure out what I want from the headers back. Anyone have any suggestions?