removing exhaust bolt from head

[98600xc]

Hey guys, I bought a new motor for my 200x and am in the process of putting it in and getting everything hooked up. I got pretty much everything hooked up and bolted in and when I went to do the exhaust, I realized the guy who had it before me but one of the bolts too short on the head. I have tried heat, oil, etc... and haven't had any luck. Do you guys have any tips/tricks I should try, this is really frustrating... thanks

[Dirtcrasher]

Nope, it usually requires removing of the head and a new SS stud installed. Nothing cheap or easy, just one of the services I offer.....

This stuff has been in place 25 years, think about a car, 10 years and all the crap breaks off...............

[tri again]

Sorry man.

That's prob why I walk around ALL my stuff with liquid wrench
(or similar) a couple times a year.

I especially hit exhaust studs. I drilled one out as part of my job interview at a repair shop years ago (and got the job)

I'd follow dc's suggestions to the letter.

Hey, topic change...
how come 2 stroke dirt bikes have springs holding
exhaust headpipes on? and we have to fool with rustystuds

[bigred44]

Sorry man.
Hey, topic change...
how come 2 stroke dirt bikes have springs holding
exhaust headpipes on? and we have to fool with rustystuds

Good question I've wondered this myself. Maybe because of the added back pressure of a 4 stroke compared to the 2 it reqires a tighter seal?

[barrett8]

its because the vibration a 2 stroke make will just break and crack the pipe a part if its held with bolts.

[WIkid500]

Is there anything left sticking out of the head? If it's broke flush or in the head get a die grinder out and flatten out the stud, center punch it and drill it out. I know DC says you need a mill to get work done, sure makes it easier but it's not always needed. A lot can be done with a good set of drill bits and patients. When drilling out a stud/bolt drill until you get to the threads and from there the remaining material is usually soft enough to dig out with a pick. ...And as for the stainless studs, they are great until they break off.

[Frankencelery]

I just went through this myself on my 250sx. I didn't want to pull the head. Dunno if it could even be done on the SX with the engine in it, so I took the whole machine to my local shop and the crazy SOB drilled it out with a hand drill and tapped it while I chewed my fingernails, afraid he'd screw up my head. Then he gave me 2 allen head bolts to use instead, and told me to forget the studs. Turns out he was right. The bolts were the perfect length, and I just left 'em.

On the 200x, if you think you're too far along to pull the engine, then pull the head off and have your local machine shop do it properly. Or send it to Dirtcrasher, and he'll do a great job on it and replace those studs with stainless ones.

[muthey]

I kind of like the way yamaha does it for theirs, they have drilled holes that you run a hex bolt right into, like frankencelery had done to his sx, I haven't had one locked up on me yet "crossing fingers now" but is a much easier way to do it not hard to drill and re-tap a hole verses putting in a new stud. Stainless is great against corrosion, but from the heat the expansion and shrinking can at times cause galling of the threads as well, it does depend on what stainless they use though some hold up better than others.

[El Camexican]

Use anti-seize anytime you mix stainless and aluminium. If you don't, a form of corrosion occures due to electrolisis. Weird stuff, but just look at the lower section of a used outboard boat engine to see an exaggerated example. Nasty stuff.

[Dirtcrasher]

Is there anything left sticking out of the head? If it's broke flush or in the head get a die grinder out and flatten out the stud, center punch it and drill it out. I know DC says you need a mill to get work done, sure makes it easier but it's not always needed. A lot can be done with a good set of drill bits and patients. When drilling out a stud/bolt drill until you get to the threads and from there the remaining material is usually soft enough to dig out with a pick. ...And as for the stainless studs, they are great until they break off.

If you want to advise the members to attempt this on your own, I hope it comes back on you. My "earnings" for these repairs are slim, they are certainly not a good portion of my income. I've done about 33 heads now; many were "attempted" to be removed by themselves, never on center or in line and it cost them more to get it repaired. 25 year old aluminum does not like old plain steel. SS helicoils with a SS stud are not a problem. Go ahead and encourage members to do this on there own to an otherwise good head with good cam journals......

I never offered my services to get rich, merely to to them the best I could at a reasonable cost.

Here a couple shots of repairs I was sent this week; With the members permission, I'll send them to you and you can do them cheaper with your Craftsmen drill. Give me your address, since it's no big deal. And post up some of your successes would you please??

http://i257.photobucket.com/albums/hh220/Dirtcrasher/101_1100.jpg

http://i257.photobucket.com/albums/hh220/Dirtcrasher/101_1099.jpg

http://i257.photobucket.com/albums/hh220/Dirtcrasher/101_1096.jpg

Just a simple hand drill should do it, then the threads spin right out; piece of cake................... :lol:

[ametzker]

Kinda hardk to explain without pics but. If you have a welder then it works great. Take a washer with the inner diameter being the same as the bolt diameter. Hold the washer against the bolt and weld in the center so the stud is now welded to the washer. Then just a weld a nut to the washer/ stud combo and you should be able to turn it out no problem. I will post a pic of this if I can find one.

[Dirtcrasher]

That practice does not work well on aluminum cylinder heads, very small success ratio. Yes it can work if there is no corrosion and steel on steel but not so hot on 25yo parts.

Does anyone understand that they don't make our parts anymore? If you screw it up, it's 80-120$ an hour at a TRUE machine shop or find a crate motor head for hundreds.

And just an FYI, I have inherited 26 apartments and this will most likely be the last of my work here at 3WW. Sorry, but I'm swamped and maybe the suggestions above will work for you.............

[3Razors]

These repairs go from bad to worse when people attempt to drill the broken stud out. Problem is most people dont have a steady enough hand to get the drill axis perfect/centered. It can be done though with alot of patience and a little luck. To make life easier one of the best gadgets I've used to drill perfectly centered holes in busted studs is the quikcenter. Use a cobalt bit with some cutting oil also as the studs become heat hardened from being in the cylinder. There is a vid on youtube that explains it best, and the price is cheap..$8 per kit or $25 for a pack of 4 sizes in metric or sae.

http://www.youtube.com/watch?v=RbDF9P1uDyk

The welding a nut on the stud works great also. I usually hit it with some Kroil or Pb blaster, let it cool about 20 mins and they usually spin right out.

[tri again]

many many possible outcomes, but remember,
ez outs and left handed drill bits are almost impossible
or absurdly expensive to remove when
they break.

Great pix, dc.

We had some crazy machinist in Silicon Valley who worked in
both aerospace and electronics industries.

He had some sort of electrolysis rig that would actually
remove steel studs from aluminum by vaporizing them by the thousandths.

Then again, he was working on million dollar pieces.

I'm sorry to throw a wet rag on this topic but I've been there, lucky until
the very last second and then oops(ed) into total hopelessness.

Most of the stuff we worked on had drillings into or near water jackets so there was very little extra room.
Or drill them like a drunken sailor and have them heli arced and retapped.

Good golly, the flashbacks.....
will they ever fade away?

[muthey]

dc I am a fellow machinist and it is a sad day when we have to give up our trade to do something else I have followed alot of your repair threads and you do awesome work. I also understand what you are saying about doing it right the first time to prevent someone else having to clean up a big mess. I guess we all have to learn from our mistakes when we make them the other solutions may work or they may not every situation is different. Good luck with the apartments, and just remember all the good machining you have done for fellow members on this site.

[El Camexican]

Removing broken studs in expensive aluminium parts is not a good place to learn. We may learn from our mistakes, but can you really afford the education?

[bentcpaw]

Can anyone tell me where i can purchase exhaust studs for an 85 250sx stock exhaust?

[El Camexican]

Can anyone tell me where i can purchase exhaust studs for an 85 250sx stock exhaust?

If you can't find studs (try Allen's Fasteners) you can buy a fully threaded bolt (longer than you need), cut the head off and make one. If you can't find a threaded bolt long enought try searching for threaded Metric rod on line and make them out of that. Be sure to run the factory end of the rod into the head and that you have dressed the cut end enought to take a nut with ease. If you don't know how to do this ask anyone who works with steel or in a machine shop.

[just ben]

most auto parts stores will have the studs. i dont see a reason to cut the heads off bolts to make studs,why not just use the bolts?

[Dirtcrasher]

Because bolts bottom out, stud threads don't.....

The hardest part is getting the old ones out; MUCHO Heat is your friend! :D

[El Camexican]

most auto parts stores will have the studs. i dont see a reason to cut the heads off bolts to make studs,why not just use the bolts?

Hey Ben! Yea, what Dirtcrasher said, unless you know what length you need, a stud is better AND you can leave them in and take the pipe off multiple times without disturbing the threads in the head. The drag bike guys came up with a spigot system where you bolt a machined aluminum block onto your head and leave it there permanently and then attach the pipe with springs like a two stroke.