Wildguzzi.com
General Category => General Discussion => Topic started by: GuzziBurger on March 27, 2020, 12:32:13 PM
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Hello,
I wish my first post was a fun mod or a cool picture. Instead, I have had many troubles with my exhaust stud. When removing the exhaust wrap the previous owner put on the bike (It was starting to smell and burn up) I removed the headers. When removing the left exhaust flange, the top of the exhaust stud broke off. No problem I say! I then screwed two nut on it as you do when you get a stuck stud. No dice, Just broke it further. I then heated it up with MAP gas torch and locked vice grips on it. Nope, broke more. Damn!Time to take the drill out. Center punch, drill, then use an easy out.
Big Mistake
You guessed it, the easy out is stuck inside the damn thing.
I now have two roads ahead of me:
- Removing the easy out with a die grinder or a hardened drill bit and putting a helicoil in which I should have done in the first place
- Drilling and tapping two new hole for the exhaust studs
Looking at the head design, it seems like there is space to drill out another two holes and rotate the exhaust flange. My theory is that guzzi uses the same basic molds for both sides of the head and there is meat to drill into.
(https://i.ibb.co/mCcnMVQ/temp-File-For-Share-20200326-192159.jpg) (https://ibb.co/mCcnMVQ)
Is this possible, have you attempted this? I've searched on the forums with no luck but please link me the thread if there is one.
In the event that this is not possible or I mess up, how interchangeable are the small block heads? I have a v7 Classic from 2015 which is a weird year for the classics.
Thank you! I'm kinda bummed out this is the first issue I have with this bike.
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You might try using a left-hand drill bit, but the E-Z out is hardened and so that might not work.
Rich A
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I learnt a few years ago to always use a LH bit when drilling a hole for an ezi-out, and most times the stud /bolt comes out without needing the ezi-out. Sorry, not much use to you now.
Drilling / tapping a pair of new holes looks like a sensible solution. Just put some bunched up newspaper in the port.
The only other way might be to spot weld a bolt to the end of the ezi-out but doing so may damage the head - although I have had that done to remove a broken stud in a fork leg
AndyB
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Or option #3 - Pull the head take it to a machine have then remove the broken ez-out and stud then install a timesert.
I vote for option #3
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Or option #3 - Pull the head take it to a machine have then remove the broken ez-out and stud then install a timesert.
I vote for option #3
Call around and see who has a Broken Tap Extractor which uses electrical current to disintegrate the ez out. Or an EDM shop with a Hole Popper - a small hole EDM drill that will burn up the ez out. Either of these methods will require removing the head. BTDT :violent1:
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Or option #3 - Pull the head take it to a machine have then remove the broken ez-out and stud then install a timesert.
I vote for option #3
3 has my vote also.
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At this point, I would try to MIG a nut onto the remnants of the ez out. If you can get a good weld, the EZ out should come out. The extra heat may help loosen the broken stud. Then I would go up one size with a left hand drill bit if there's enough stud meat left to grab. But I wouldn't hold my breath.
After that, pulling the head is next. Not cheap, not fast but the most practical way to fix it without getting the repair far off center, misaligned or compromised.
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Google "alum remove stud" and you'll get a bunch of hits. Essentially, alum will dissolve steel but not touch aluminum. You'll need to keep it warm - like keep a light bulb close, but that's about it. The tricky part is figuring out a way to keep the alum/water mixture up against the stud. Guys have used clay, but in this case you might need to build a well with epoxy or silicone seal. Perhaps make a plastic cup that bolts to the remaining stud, closes off the port and keeps the solution up against the broken stud.
The easy way is to remove the head - easy after it's off, that is.
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Nasty.
The usual trouble the rest of us smallblocks have with the studs is that the nuts get seized on the stud & the whole stud comes out with it when removing the headers.
I thought the Classic was made from 2009 - 2012, the same 2 throttle body engine as the 750 Breva & the Nevada - so heads from those are likely interchangeable. From (around) 2012, came the single throttle body Special, Stone & Racer. There were slight changes here, not only to the outside shape of the head, but it's internals as well. If yours is a 2TB, you've a bigger range of possibly cheaper heads to choose from, should you want a spare. I don't know if the V7 II heads are different from the earlier 1TB versions, but the V7 III, with the change to hemi heads, most certainly is.
BTW, I have a spare set of heads from an early carbed Nevada, but I'm in Sydney.
Good luck. Let's us know how you get on.
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The usual trouble the rest of us smallblocks have with the studs is that the nuts get seized on the stud & the whole stud comes out with it when removing the headers.
This happened on my Breva.
While it was out I freed it up with the vice, heat etc, then, on the frozen one plus all the others I gave the threads a good coating of copper anti-seize and have had no further problems.
Hope you are able to ultimately solve your dilemma easily (and cheaply :wink:)
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Thanks for all the ideas. Did not even know about alum !
I will definitely update back with what I ended up doing. I'm going to call some shops and hunt down the gaskets I need if I end up going that route.
Fun thing is I just finished building a bike (a Yamaha xs650 Special) and I bought this v7 to not have to worry about.
Very good info about the interchangeability of the heads.
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Other than the inconvenience once the head is off it should be an easy fix. Then you should have many trouble free miles!
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This issue has always made me paranoid. I put copper anti-seize on mine on Day 1, and every oil change I give each of them several rotations so they never get frozen.
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This issue has always made me paranoid. I put copper anti-seize on mine on Day 1, and every oil change I give each of them several rotations so they never get frozen.
An ounce of prevention... :thumb:
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In all my years I never really had a EZ out work if the bolt is sized. The head has to come off,period. Maybe you can find a machine shop that will go in there with a carbide cutters. If it's a tapered EZ out it should come out easy once you get down a bit. At that point the broken bolt is no problem. Use SS steel studs when your going to put new ones in. Might as well pull the other one too while you have the head off in case it breaks off too.
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I like to use nickel based anti seize on exhaust just for the color when it oozes out of the joint.
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I was lucky enough to get exhaust studs with the bike and have swapped out all the others for new ones. I chased the threads with a tap to clean them out and put some grease on the bolts to prevent them seizing.
I'm adding this to the list of things to check on a bike!
Now to find a head gasket and a valve cover gasket for the head...
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GuzziBurger
Don't try anything else without getting the Aluminum really warm. If some numb-skull put the steel exhaust stud or bolt into a warm aluminum hole and tightened it --- then you won't get it out ! :embarrassed:
Do you have any idea how much aluminum swells when heated ? Steel don't even come close. But , cold steel into a hot aluminum hole is never a good thing to do.
If you can ever get a grip on that steel bolt again , then add a heat sink to the bolt to shrink it while leaving the aluminum hot --- then you might have a chance ??? :undecided:
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There comes a time where you must admit defeat, before you do more damage. Been there.
Remove the head and take it to a machinist.
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I have been in this situation many times. What I do is get a quality drill bit slightly smaller then the stud
and start drilling into the stud. Check often and the EZ out will loosen and you will be able to get it out
using a dentist style pick or equivalent. If you are straight on the stud at this point you can keep drilling
and the stud should be able to be screwed out as the metal gives way. Disclaimer: If you are off center too much
you will have to use a tap to clean up the threads or go to the next hole size up and use a Helicoil.
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Well, many years ago (8 or 9?) ran into this. Finally found a local machine shop that does EDM. Brought it to them, and noticed several Guzzis - they were his and he was wanting to sell. Connected him up with someone on this forum and bingo! Good luck with removal.