Kawasaki VN750 Forum banner

1 - 20 of 46 Posts

·
Git-R-Done!
Joined
·
282 Posts
Discussion Starter #1
Ok - today my impatience has done me in. I was trying to remove the right-side exhaust pipe, and instead of being smart and soaking the nut and bolt with some WD40 and waiting when I encountered resistance, I tried pushing just a little bit harder, and then - SNAP. Yep - snapped the dang bolt clean off (pic attached).

So now, I am pretty freaked out obviously, and wondering what I need to do. First question is this : it looks to me like there is some kind of exhaust manifold maybe? Or is it the cylinder head, that the bolt actually comes from? There is some fixture with four similar looking nuts on the front of the cylinder, just behind the radiator, and I am wondering if I am going to need to replace it...? And if so, what it entails.

Another question would be (and I seriously doubt this) if I took it to a shop, could they tap it out, and resink another bolt or something? I am REALLY hoping there is some fix that isn't all too hard or all too expensive. The weather is awesome, the bike was running great, and I was merely trying to put on some brackets for mounting highway pegs I got from Chad. Ugh! I knew I should have soaked it - I was just in a hurry, and as the old adage says - haste makes waste.

As always, any and all help is greatly appreciated. In fact, it is so much appreciated that I am becoming a site supporter as of today. Lord knows, this is one thing in my life that is worth far more than I have (not yet) paid for it!

:smiley_th

AZ Kev
 

Attachments

·
Linkmeister Supreme
Joined
·
7,960 Posts
Looks to me like you can take the 2 collar pieces off the exhaust pipe and the broken off stud will still project from the manifold.
Soak the stud with PB Blaster for a day or two and give the end a couple of good whacks with a hammer to break any corrosion seizure on the threads.
Try gripping the stud with vice grips to turn and "worry" it back and forth until you can turn it all the way out.

Clean out blind hole with a metric tap and compressed air.
Use anti-seize on the new stud when you install it.
 

·
Git-R-Done!
Joined
·
282 Posts
Discussion Starter #4
Thanks for the advice Gordon - you rock! I got so freaked out, I couldn't imagine something so simple. I appreciate it man. I will do exactly as you said and let you know how it goes.

And I SOOOO wanted to ride this weekend, as it is gourgeous. Dang it all anyway! Lol : )


AZ Kev
 

·
Sparky!!!
Joined
·
8,697 Posts
and please don't heat the studs... this works with steel on steel bolts, but on aluminum on steel... not such a great idea... you will get the bolt out easy, but you won't be able to clean up the whole well enough to add a new bolt with out welding the hole closed and re drilling and tapping the hole.
 

·
Git-R-Done!
Joined
·
282 Posts
Discussion Starter #6
Installing new stud...

Thanks for the replies all.

Gordon, I was wondering - how will the new stud be installed? I mean, is it threaded on both ends, such that it will screw into the manifold? Or is it simply a press fit?

Forgive me if I am mis-stating this, or if I seem a little ignorant about this stuff. I have some mechanical skills, but there are a number of things I have not yet done, and this is definitely one of them. I am familiar with replacing the mounting studs on car wheels, but not sure this is the same type of deal.


AZ Kev
 

·
Linkmeister Supreme
Joined
·
7,960 Posts
Thanks for the replies all.

Gordon, I was wondering - how will the new stud be installed? I mean, is it threaded on both ends, such that it will screw into the manifold? Or is it simply a press fit?

Forgive me if I am mis-stating this, or if I seem a little ignorant about this stuff. I have some mechanical skills, but there are a number of things I have not yet done, and this is definitely one of them. I am familiar with replacing the mounting studs on car wheels, but not sure this is the same type of deal.
AZ Kev
I imagine the stud is threaded on both ends, but haven`t had the pleasure of replacing one yet.

Can`t be a press fit like an auto wheel stud.
Wheel stud is pressed in from the back of the hub, and has a rim like a bolt head to hold it and tighten the nut against.

To install a new stud - screw two nuts on the top end of the stud and jam them tight together with a pair of wrenches. Then you can apply torque to the top nut with a wrench to install into the blind hole.
Remember the anti-seize.
Two wrenches to unjam nuts and remove.

If you need more help, just ask.:)
 

·
Banned
Joined
·
448 Posts
In response to your original question, there is a manifold mounted to the head with 4 bolts.
If you have to, you can carefully remove the manifold to get at the broken stud easier.
If you can't get the stud out, there are several places to get a replacement. Most bike salvage yards have them for pretty cheap. There are several on E-Bay as well, and there is a link on this site for Vulcan parts for sale there.
As was stated earlier, you can soak the stud with PB Blaster or the like, and work the stud out if there is enough "meat" to get hold of.
Good and happy riding.
 
  • Like
Reactions: niterider

·
Sparky!!!
Joined
·
8,697 Posts
the studs are threaded into the manifold, not pressed in... the reason you work the stud back and forth as you twist it out is to help keep the threads clean of rust and lesson the binding.
 

·
Premium Member
Joined
·
4,778 Posts
I would use threadlocker rather than antiseize on the internal threads. It will minimize corrosion and help hold the stud in place. Use antiseize on the external threads so the nut doesn't grab again.
 

·
Sparky!!!
Joined
·
8,697 Posts
I would use threadlocker rather than antiseize on the internal threads. It will minimize corrosion and help hold the stud in place. Use antiseize on the external threads so the nut doesn't grab again.
loc-tight is a big no-no on exhaust bolts and studs... as an experienced engine builder, always use ant-seize on exhaust bolts and spark plugs. anti seize just keeps the threads from welding them selves together from heat. It also keeps the moisture out... Thread Lock products become brittle with heat and can cause serious problems when trying to remove the fasteners at a later time.
 

·
Git-R-Done!
Joined
·
282 Posts
Discussion Starter #12
Bill - thanks for verifying my thoughts about the manifold. I actually looked on eBay last night and saw one available for around $25, if I need to go that route.

To slim, Gordon, and fc - thanks for all the added tips about how to get it out, how it goes in, and what to consider when doing so. I soaked it in some PB Blaster last night, giving it a few taps to hopefully start loosening it. I sprayed it again this morning with some more PB and gave it a few more taps with the end of a ratchet drive. I am planning on my first attempt to GENTLY convince it to come out of there this evening. I will let you all know how it goes.

It sounds like, at best, I will simply have to put another stud in there, and at worst, replace the exhaust manifold. Fortunately, I think I can handle either one of those tasks, thank goodness. But only because of all you, and for that, I am VERY grateful.

Hope you all have a fantastic weekend = )

AZ Kev
 

·
Linkmeister Supreme
Joined
·
7,960 Posts
Kev, how much of the stud is sticking out from the manifold? 1/4"? 1/2"? more?
Is there enough to get a good grip on it with a pair of vice grips?
 

·
Linkmeister Supreme
Joined
·
7,960 Posts
and please don't heat the studs... this works with steel on steel bolts, but on aluminum on steel... not such a great idea... you will get the bolt out easy, but you won't be able to clean up the whole well enough to add a new bolt with out welding the hole closed and re drilling and tapping the hole.
slim, is the exhaust manifold made of aluminum?
I thought it was cast iron. The head is an aluminum alloy I think.

IF the manifold is cast iron, you could carefully play a propane torch on the stud, OR heat and expand the manifold right next to the stud while trying to keep the stud itself as cool/small as possible. If you choose to try heating the manifold in this manner, I would take it off the cylinder head first. But be careful and do not break anymore fasteners.:( <G>

Kevin, you might find some other helpful instruction on this online repair course too.
http://www.dansmc.com/MC_repaircourse.htm
 

·
Sparky!!!
Joined
·
8,697 Posts
you are right Gordon, i forgot the manifold was not part of the head... But I would still try to get it out with vice grips, and if that doesn't work, using a grinder to cut it off flush with the manifold and then drilling it out a couple sizes to small then get a reverse drill bit 1 size smaller than the threads... finish it all off with the correct size tap if needed...
 

·
Git-R-Done!
Joined
·
282 Posts
Discussion Starter #16
Ok guys - here is a good pic of how much of the stud is sticking out (about 1" of it or so, I think).

Looking closely at it, it appears as if it has been welded into place. I was able to get some vice grips on it, but it sure doesn't act like it's going to move. I am going to soak it some more tonight and see what tomorrow brings.

I have never actually tapped a hole before (insert joke here! Lol!), so I don't know if I even have the tools necessary to do it. I do have a corded (ac) drill with a number of bits. But I don't have any actual taps or anything.

Is it something that someone with some mechanical skills can do without messing up too bad? Or would I be better off to take it somewhere where they can do it for me?

AZ Kev
 

Attachments

·
Registered
Joined
·
686 Posts
Ok guys - here is a good pic of how much of the stud is sticking out (about 1" of it or so, I think).

AZ Kev
A good picture would be clear.
Definitely enough meat. SOAK it with PB Blaster or Deep Creep (a Seafoam product and my recommendation).....it will come out. SOAK SOAK SOAK. If it takes two days, so be it.
 

·
Linkmeister Supreme
Joined
·
7,960 Posts
X2 to Doc`s instructions^^^
I have never actually tapped a hole before (insert joke here! Lol!), so I don't know if I even have the tools necessary to do it. I do have a corded (ac) drill with a number of bits. But I don't have any actual taps or anything.
You are not actually cutting new threads, just cleaning corrosion and crud out of the old ones. You can do it. You can buy an individual tap, but if you are going to continue wrenching on the bike you are eventually going to need other sizes too.

Buy an inexpensive set of metric taps and dies from someplace like Harbor Freight. Probably cost about $20-30. If you have a choice get dies with a six sided circumference instead of circular. They are more versatile because you don`t have to use the long handled die holder to turn them, and can use an ordinary open end/box end wrench or a socket to turn them in a tight spot.

Mine has sizes 3, 4, 5, 6, 7, 8, 10 and 12 mm diameter taps and dies, with two different thread pitches for each diameter, plus a pair for 1/8" NPT. That should cover most of your needs for a motorcycle.

Use lots of lube (WD-40 or even motor oil is ok) when cutting. Go slow, turn in a half turn or so at a time then back out if/when resistance increases. Clean dirt out of the tap flutes, spray in more lube as needed and repeat.

Do not snap the tap off in the hole, because then you will need a new manifold.
Tool steel is as hard or harder than the drill bits, so cannot be drilled out.
 

·
Giggity!
Joined
·
4,307 Posts
I'm jumping in late here but I have totally been down this road before. I ended up braking a tap & called'er quits. I bought a new manifold & had it replaced in no time. If you end up going with a new manifold or have removed your exsisting one. Don't forget to replace the gasket between the manifold & the cylinder head.
 
1 - 20 of 46 Posts
Top