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HELP!!!!!!! FRONT EXHAUST NUTS SHEARED OFF

Posted: Sun Jul 05, 2009 6:53 pm
by crofty7
:?: Some one please help me :?:

When stripping my NC30 (giving it a full service and set up) i noticed that one of the front nuts had sheared off from the cylinder head. I thought it best to replace all the threaded studs, nuts and exhaust gaskets. As the bike is already stripped at the front end i thought i would do this work whilst nothing was in the way. Off came the first nut no problem, the other two however sheared off with no force at all. On all three studs there is only about 5mm sticking out of the head.

Where do i go from here? What is the best way to get the threaded studs removed? I assume the rear ones should be ok as they are sheltered by the mudgaurd?

Re: HELP!!!!!!! FRONT EXHAUST NUTS SHEARED OFF

Posted: Sun Jul 05, 2009 8:07 pm
by mrdidlydingo
three options

1. drill and easy out, ballache will work, prob have to remove engine to be accurate.

2. find two nuts which sit over the stud ie 1-2mm bigger than the original, weld through the centre of the nut onto the stud, let weld cool slightly, (stop glowing then count to ten) wind out

3. stud remover hard to get onto the cyl head and least likely to succeed

In my experience I would go for No. 2 every time it works a treat as you heat the stud as you weld the nut on which helps to release it,

I have tried option 3 it left me crying as the stud remover basically chewed off everything that was sticking out which then results in using option 1 which is a ballache!

Re: HELP!!!!!!! FRONT EXHAUST NUTS SHEARED OFF

Posted: Mon Jul 06, 2009 7:00 pm
by crofty7
oh ball bags.

When you tried the stud remover did you heat up the stud and cyl head?

This looks like it's going to be a bitch no matter what i try. Looks like i'll let someone who knows what they are doing get them out.

Re: HELP!!!!!!! FRONT EXHAUST NUTS SHEARED OFF

Posted: Mon Jul 06, 2009 7:25 pm
by viper_biker
Welcome to the club. When I fitted my full system the same thing happened to 1 of my header studs. A lot of patients and a drill to drill out what was in there then tapped a new thread in. It's a major ball-ache, and takes forever and a day but was the only feasable option for my, other than sourcing a hew head and I certainly wasn't going to do that (unless I was going to do a big-bore)

Re: HELP!!!!!!! FRONT EXHAUST NUTS SHEARED OFF

Posted: Mon Jul 06, 2009 10:24 pm
by hunter
Go with mrdidlydingo,weld a nut on what'sleft of the stud let it cool,out it will come.

Re: HELP!!!!!!! FRONT EXHAUST NUTS SHEARED OFF

Posted: Mon Jul 06, 2009 11:13 pm
by CMSMJ1
If it comes to it, swapping a head over is not that much of a ballache. You get to do a bit of polishing and can also lap th valves in too...and take out the quietening gears etc..lol

Saying that...Mr DD is right, get a nut welded on or flat the end and mole grip it out

Re: HELP!!!!!!! FRONT EXHAUST NUTS SHEARED OFF

Posted: Tue Jul 07, 2009 12:06 am
by mick.mh2racing
mrdidlydingo wrote:three options



2. find two nuts which sit over the stud ie 1-2mm bigger than the original, weld through the centre of the nut onto the stud, let weld cool slightly, (stop glowing then count to ten) wind out
That is a damn fine idea, never been in this position but I'll bear it in mind for when I am.

Re: HELP!!!!!!! FRONT EXHAUST NUTS SHEARED OFF

Posted: Tue Jul 07, 2009 7:56 pm
by crofty7
Thanks for the advice all.

One of the three studs has about 10mm of thread on it so i will practice on this one first. I am going to try heating up the stud and cylinder head and attempt to remove it using a stud removal tool (The one that grabs the stud, not the one you that you have to drill through the centre of it first). If this doesn't work then i guess it will be off to my mate the mechanic to drill the little shits out. But this will be expensive as when i told him about it and asked how much it would cost i'm sure he developed a chronic form of asthma (huge inhales)!!!!!!!!!

The two worst ones only have 5mm of stud sticking out of the head. Would this be enough to weld a nut onto it cos there is no way two would fit on?

For the rear ones i will heat the studs and nuts up first till they glow a bit orange then this should free them up. I hope!!

Re: HELP!!!!!!! FRONT EXHAUST NUTS SHEARED OFF

Posted: Tue Jul 07, 2009 10:30 pm
by hunter
5mm is plenty,if you have any thread left screw a nut on then fill the nut with weld,if no thread
drill the nut out so that it will slide over the stud,then weld it on job done.
PS.if you put heat to the rear one's let them cool before you attempt to remove them.