carb boot studs

I managed to snap the heads off a few of the studs that hold the boots - that go between the carb and the cyl head - to the cyl head. Additionally i managed to snap off the tip of an easy out in one of the studs. They pretty much snapped off flush to the cyl head so putting a locking wrench on the stud is out of the question. The motor is still in the bike so there is not enough room to get any of the drills I have into the area to properly drill into any of these stud holes.

My bright idea is to grind all the studs down flat and flush to the head and weld a new stud over the top. Obviously with the head being aluminum the choice for the stud and therefore the hardware would also be aluminum. Then new gaskets and boots all the way around.


anyone have any better ideas or anything I may not have considered on why I shouldn't go ahead with the new studs?

 

Do yourself a favor and do it right! You should have stopped trying to remove those stuck Cap Screws the moment that the first one broke.

If you had checked-in, here, before embarking on the disaster you have ... you would have learned that we do not recommend trying to remove those Cap Screws ... at all!

They are non-hardened, soft steel and break-off under moderate unloosening torque.

Take the Head off.
Bring it to the Machine Shop and Machine Skills Department of the Finest Technical School in your area and politely ask if they wouldn't mind tackling your "Real World Dilemma".

If the School has a sharp Department Head in the Machinist's area ... they'll be able to burn-out the Easy-Out ... drill-out the broken studs and make you whole again.

You have entered The Twilight Zone ...
You cannot recover from this mistake without having it done right.
Further attempts to rig something up and try this and that is only going to make the situation exponentially worse ... until you do something that just flat-out ruins the Head.

Sincea the Head has to come off ... you might as well buy a set of valve seals and have the Valves Seals replaced and the Valves Lapped-in while the Head is Off.

Offer to make a donation to the Departments "Expendables Fund"
Take advantage of those learning how to be the best Machinists they can be and bring that Head to a Technical School and let them FIX IT ... right!

 

You may not advise taking those cap screws off but when the boots need to be replaced there isn't much choice.

 

I'm with Rick. Fix it right or don't bother at all.

 

thanks, dad.

 

Rick is almost a god Iv taken his advice when I snaped the threads off a spark plug in my head and i spent a bit of $ but I could have spent a lot more if I didnt listen and thanks to you Rick for that. Take it or leave it but I think weilding it would be the worst thing you can do.

 

because it's not what rick said to do?

 

Wow. You asked for advice, you got advice. Use it, don't use it, that's up to you. These guys are just trying to offer the help you asked for. If you don't like it, that's your choice. Just say thank you and do what you think is best. Getting snotty about it isn't going to help anything.

 

Actually what I asked was if anyone could provide reasoning as to why what I have in mind won't work. To which no one seems to have anything better than 'its not "right"' or 'because jam master flash said to do the other thing".

If I wanted to know what someone that works at a dealer or a machine shop had to say I would have listened to the guy that works at the dealer and the machine shop. If I wanted to spend a bunch of money and rebuild a motor, thats what I would do (spend a bunch of money and rebuild a motor). I've got enough projects and rebuilds going on that adding another just for kicks doesn't really appeal to me.

I'm not going to dump a few hundred dollars into a bike that cost me $400 unless I absolutely have to. Other than needing a new boot the motor has great compression and runs absolutely fantastically. I have zero motivation to open it up and take a chance of changing that. Exterior studs are very minor. Compression and pistons and heads are very major. I don't want to get into major work over minor problems - if at all possible.

I guess a better way to phrase it would be: "I can't think of why doing what I proposed wouldn't work. Can anyone else give me any reasons to consider as to why it wouldn't?"

 

you want 2 weild it and heat the head till it warps lets see metal stud aluminum head yha good idea go ahead im all for it. Not a way 2 make friends here.

 

you know aluminum is a metal too, right?

 

noted. moving right along....

 

if you could cut a slot in the stud with a dremmel wheel maybe a screwdriver could turn it, it cant spread open 'cause it's in a hole
so what if you slot the head a little it won't hurt anything
it's been heated and abused maybe it'll come loose ?
question : how you going to weld a stud to the the head without a fillet at the base that keeps the manifold from setting flat ?
if someone was good enough to do that they could tig a new head on the busted stud and use a wrench
better yet just tig the new manifold to the head and be done with it

 

I think an alternative plan would be to pull the engine and have some space to wield the tools you'll be needing to drill-out the broken studs and take a shot at bringing-out the broken ends with heat and a set of extractors.

You're going to have to buy a Diamond or a Carbide Bit to grind-out the broken-off EasyOut.

That's going to take you some time and a Bit or two ... and you'll be working on Hardened Steel with not much surrounding the hole.

If you can get the EasyOut -- out ... you have a shot a drilling-out the Studs.

You can neither drill them out and try heat and extractors ... or, drill them out completely and:
Fill the holes with weld and drill and retap ... or,
Fill the holes with a piece of aluminum rod and weld, grind drill and retap.

Or take it to a Machine shop for some precision machining.

I don't have a good deal of confidence thinking that the job is going to get done with the precision necessary trying to do it in place.

I remember being where you are right now a long time ago.
I snapped off two Cap screws and was up the same creek you are right now.

The only thing the manager had to say about it was:

"Don't go home until that Head is off there and ready to be sent-out!"

 

I probably shouldn't be jumping in here, but I think I will anyway.

Rick, I'm wondering if maybe you came across a bit more harshly than you intended. If what Mac says is correct, that the manifold boots needed to be swapped out, then removing those bolts, I imagine, is pretty much mandatory.

OTOH, Mac11, you might want to ease up on your tone as well. I realize you're in panic mode here, but biting everyones' head off isn't going to help matters, and nobody is going to want to try and lend a hand.

Now, then, let's see if I have this right. Mac snapped off a couple of bolts, and wants to weld aluminum to the broken studs to try and extract them. However, as the bolts are mild steel, welding aluminum to them would be a tad bit difficult. Adding to the complexity of the situation is that one bolt has a broken extractor in it.

Did I miss anything?

I haven't been in this situation myself, but my two cents: Pull the head. If nothing else, it'll give you more room to work.

 

I apologize if I came-off harshly. I, for one, shouldn't be doing that.
Anyway, the welding aluminum to steel idea isn't a sound one.

Trying to do anything with the Head still within the confines of the frame isn't a good idea either.

I want the Member to get his Bike fixed, for sure ... but, I don't want him to do further damage trying to do what ... IN MY OPINION ... would be ill advised.

This is a tough spot to be in.

I's sorry it's happening to a guy. I wouldn't wish it on my worst enemy!
I hope he gets the Studs and EasyOut out of there and recovers from this in short order.

But, I don't think it's a "Short Order Job!"

 

first, I would like to clarify. I had no problems with what Rick suggested and was not aiming anything at him. He's now revealed he does this professionally and it is the same advice I got when I brought the local dealer, a friend of mine, to look at the situation - pretty much to the 'T'. He is actually who snapped of bolts #3 and possibly 4 if memory serves. I was fully aware that at some point it would be suggested and with the detail in which Rick outlined everything I can see he is a very knowledgable guy. I suppose I forgot to leave a cordial response for him letting him know I appreciate his input.

It was the nut swingers jumping on after the fact with no thoughts of their own with "if you don't do it ricks way then f*** you" that pissed me off. If i wanted someone to tell me "if you're not going to do it right dont do it at all" I would have swung this project past my fathers house. Fathers are always good for that kind of saying. If I wanted this project done "professionally" I would have dropped it at a shop and come back a few weeks later, opened my wallet, doubled the price of my bike (or more) and been done with it. But I can say from experience the job can get done "right" or correctly by other means with a little ingenuity and elbow greese. THAT is the point of this thread.

Second I'd like it known that I'm not a little kid in panic mode. This happend a couple of months ago. When we broke the easy out and started spinning in circles I put the project on the shelf. I had enough going on at the time, winter was upon us anyway - i lost 2 weekends at the end of the season - and figured a break from the situation could be of some benefit to all parties involved.

Third, I am talking about welding aluminum (new stud) to aluminum (head) as the old studs are flush with the head or already down into the holes. What I have in mind is a stud with a flat base much like a wheel stud for a car, but obviously smaller. The base of the stud would be able to be checked for square and plane so it would be known that the new boot/gasket would bolt up and snug up and not leak air.

As I said before I would really prefer to not break open a perfectly good motor over a couple of studs. That seems a little silly when you sit back and think about it. I've rebuilt several car piston motors and quite a few rotary motors over the years. The problem is not that I can't, it's that I don't think it should be necessary for such a task. The other option that has been kicked around the garage is what Rick just brought up. Pull the motor, in tact, to have more room to work. I've gotten a couple of suggestions by PM that I am tempted to try out before I start tearing this thing down any further. I may try slotting it for a screw driver as well and see how that turns out. Afterall this was the toy I bought with all intentions of doing no mechanical work on and not diving in and learning the ins and outs of - I have enough of those - just put gas in and ride. :roll:

 

just a thought here, gunsmiths use carbon steel taps so if one should snap, a sharp smack with a hammer on a good punch will shatter the piece left in the hole
i never tried it on a ez-out

 

I'll jump in as well, as I actually have experience with snapping off a head bolt on a boat motor, and welded a threaded stud directly to the snapped off bolt. The "fillet" of weld was ground down a bit. It held 35 LBS of torque, so I'd say it was a successful repair.
I believe mac11 was wanting to weld up an aluminum stud instead of steel.
Steel will stick to the steel that's in there; aluminum would need to be larger and would require more heat to do the job right. Steel welding would be a quick zap--no head distortion.
Granted, I didn't have a bike frame in my way, but I gotta say if mac11 wants to try something different, and succeeds, he would be providing an alternative to pulling the motor, messing with the timing chain, gaskets, machine shop charges--ETC.

Go for it - - weld on steel studs

 

The problem with welding steel studs on is going to be getting the new studs normal enough to the head on 2 planes so that the boot and gasket will snug up and not leak air. With as far gone as the original studs are I'm not sure thats going to be possible without rigging up extra pieces to hold everything at (near) 90* angles on 2 planes. Whereas if I use an aluminum stud with a planed base - like a common wheel stud (see image below) in the appropriate size, all that will need to be done will be a basic lap or 'T' joint (however you chose to look at it) around the base of the stud.

 

Hope this helps you--to align the threaded studs perfectly, whether they be steel or aluminum, trace the hole pattern on to a piece of paper, then copy to a 2X4 and drill square in a drill press. 8 holes.
Thread a few pieces of metric threaded rod into the holes that you were successful at removing the cap screws. That aligns the 2X4.
Now you don't need to find miniature aluminum wheel studs.
(although Chacal might have those) You also won't have such a large "fillet". Now your only problem would be to find aluminum threaded rod, or use solid rod and use a die to cut new threads.

I'd go with steel since I don't have aluminum welding experience.
I do know that experienced aluminum welders can work majic!

 

That would potentially work except I believe I successfully removed all of 1 cap screw. On top of that There are also still 2 boots (4 studs) on the bike (left hand side) that are in good enough condition to not need to be replaced. With this mess that taking those screws out has created I don't want to take those 2 off, ever. On top of that now you are talking about welding in a small area in between the head and a piece of 2 x 4. You've again given yourself a tiny space to work and you are proposing trying to get into those small holes to weld steel in that tiny area.

as for aluminum welding I have done it in the past and I also have a friend that is a welder by trade. Aluminum welding is no problem if you have the right equipment and some experience. And this happens to be one piece that I do have available.

I'm also planning on threading solid aluminum rod. I have plenty of source for exactly the part I plan to use as well.

 

You still have the obstacle of having steel where you want aluminum. I don't know too many welders that would try welding the aluminum on over the steel fragment.

With the Carbs off, you're only an hour or two away from having the engine out of the frame.
I'd ... at the very least ... take the engine out of the frame and take advantage of not trying to do precision work in a confined space.

If you have unfettered access to the places wherea the studs are broken off and want to try a time and energy saving maneuver ... I'd go get a Dremel Tool and the Wand Attachment.

Using a Bit strong and sharp enough to remove the EasyOut Fragament ... I'd work to get that fragment out and then I'd do some drilling on the soft steel stud fragments.

You can either:
Drill the old stud until you can use the biggest EasayOut in the selection to tey and remove the ... what will be a sleeve by then ... and hope for a clean extraction ... or,

Drill out the remaining inside diameter of the "Sleeve" and fill the Stud Hole with weld and drill and re-tap it ... or,

Fabricate some new Studs with and oversize that will fit the Head and cut new threads on the exposed side to slip the Manifolds over to button them on the Head.

In my opinion, the job is going to require that the Steel Fragments are removes otherwise the aluminum weld isn't going to be successful with the incompatibility of the two metals with their ferris and non-ferris make-up rendering the joining of the two by welding virtually impossible.

Don't forget that the Industrial Division of Black and Decker's HeliCoil Division in Connecticut makes a HeliCoil for just such a repair job.

Ask for Steve Devine

http://www.emhart.com/contact/loc/usa.asp

http://www.emhart.com/products/helicoil.asp

 

Mac11,
I'm going to chime in here. While I have never had an XJ head stud snap on me (still praying I never do), I have had piles of them snap on my VWs.
Rick's advice is sound. I would avoid all of the hassle of trying to line up a stud to weld it to the head, while possible, the chances of misalignment on the vertical axis are great and greater on the horizontal. Additionally, the heat of the process will more than likely cause a bit of warpage to the port and may lead to difficulties in sealing it. For the headaches avoided, I'd pull the head. Safer and better results.
Install new studs with anti-seize, eliminate the broken stud syndrome.
When I had an easy-out snap in my block, I had a welder TIG a small tab of steel onto the broken easy-out and he used a pair of pliers to twist out the stud, easy-out and all. The heat cycle tends to expand everything and make removal easier. Mind you this was on an iron block but the method works if done correctly. I've no knowledge of your skills with the welder but I would leave such work to someone who lives, breaths and eats welding rods.
Not to knock your idea, it is plausable but, in view of several members experiences including mine, we are offering our best advice. This is meant to save you time, frustration, money, and your sanity.
Props Schmuck!

***Oops! Wrote this before I noticed page two! Doh! I hope you get it nailed down Mac!****

 

Pollock reminded me: I've never done it but I've heard of screw extractors being shattered too.

I wonder if you could anneal the extractor so it could be drilled?

Finally, and I feel like a broken record because I suggest this so often: A little bit of heat on the aluminum bosses often make the steel fasteners very easy to extract.

 

Helicoils have saved my bacon on numerous occasions

 

I think at this point the plan is to take the motor out and assess the situation. Maybe it's just in my nature or because I'm stubborn but I will probably try the least invasive and progress up from there as necessary.