Author Topic: Need help now - exhaust screw stripped. Results....  (Read 5245 times)

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Offline sparty

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Need help now - exhaust screw stripped. Results....
« on: August 24, 2006, 11:37:41 AM »
Trying to put on my new exhaust and the PO stripped one of the exhaust flange screws.  It is a total loss.  I tried to cut a slot in it so that I could use a straight bit, but there isn’t anything to grab.  How can I remedy this situation?  I need help fast.  All of the other screws came out smooth.  Also, how do you dig out the old exhaust copper gaskets?

Thanks,
Sparty
« Last Edit: August 26, 2006, 02:44:50 PM by sparty »
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Offline StevieMac

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Re: Need help now - exhaust screw stripped.
« Reply #1 on: August 24, 2006, 11:52:31 AM »
Thy copper gaskets come pry out pretty easy with a sharp flathead screw driver or knife. 

Are you talking about the studs coming out of the head that the exhaust bolts too? I hope not, those a a b!tch.  Or is your motor the earlier style?
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Offline sparty

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Re: Need help now - exhaust screw stripped.
« Reply #2 on: August 24, 2006, 11:56:25 AM »
Thy copper gaskets come pry out pretty easy with a sharp flathead screw driver or knife. 

Are you talking about the studs coming out of the head that the exhaust bolts too? I hope not, those a a b!tch.  Or is your motor the earlier style?

I am talking about the exhaust bolts (screws in my case) and they are a #$%*.  I am thinking I may have to drill it out and retap the SOB.
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Offline StevieMac

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Re: Need help now - exhaust screw stripped.
« Reply #3 on: August 24, 2006, 12:02:14 PM »
Gotcha.   I had to use an impact driver to get mine out.  Drill and tap as an absolute last resort. 

Oh how I wish I had that advise before I drilled........
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tmht

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Re: Need help now - exhaust screw stripped.
« Reply #4 on: August 24, 2006, 12:10:43 PM »
Gotcha.   I had to use an impact driver to get mine out.  Drill and tap as an absolute last resort. 

Oh how I wish I had that advise before I drilled........

I concure... $20 hand impact driver has saved me from getting out the drill over a dozen times on my bike.

Offline sparty

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Re: Need help now - exhaust screw stripped.
« Reply #5 on: August 24, 2006, 12:13:53 PM »
That is the problem, I already tried my impact driver, the screw was already dished too much.  I'll post a pic of the screw in a few minutes.  You will see how fubar it is.

Sparty
1972 CB750 K2 Cafe' Style




GO AWAY SNOW AND COLD!  Can you see the Hot Rod wants to run...
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tmht

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Re: Need help now - exhaust screw stripped.
« Reply #6 on: August 24, 2006, 12:15:57 PM »
heat, pb blaster over and over again... That is the only other thing I can think of before getting out the drill.

Offline sparty

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Re: Need help now - exhaust screw stripped.
« Reply #7 on: August 24, 2006, 12:24:22 PM »
Here is the best pic I was able to take.

1972 CB750 K2 Cafe' Style




GO AWAY SNOW AND COLD!  Can you see the Hot Rod wants to run...
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Offline StevieMac

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Re: Need help now - exhaust screw stripped.
« Reply #8 on: August 24, 2006, 12:27:25 PM »
I'd try an extractor before I drilled it out completely at least.  Lots of PB blaster and heat as mentioned (well not TOO much heat...).
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Offline cmorgan47

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Re: Need help now - exhaust screw stripped.
« Reply #9 on: August 24, 2006, 12:27:51 PM »
liquid wrench, heat, and easy out?
good luck.
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Offline Rushoid

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Re: Need help now - exhaust screw stripped.
« Reply #10 on: August 24, 2006, 12:45:09 PM »
liquid wrench, heat, and easy out?
good luck.

Ditto
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Offline DME

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Re: Need help now - exhaust screw stripped.
« Reply #11 on: August 24, 2006, 12:55:40 PM »
Do you have access to a MIG-welder?

If so, take a nut that´s approximatly the same size as the head of the screw.

Weld it onto the head of the screw through the hole in the nut.

The heat from the weld will help break down the bond between the cylinderhead and the bolt.

Then use the nut to unscrew the bolt...

That´s what I would do  :)


Cheers and good luck!
Daniel

Offline colb

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Re: Need help now - exhaust screw stripped.
« Reply #12 on: August 24, 2006, 01:03:00 PM »
http://www.boa-uk.com/boa_grabit.html#

These are available in the UK, not used them but maybe worth a try.

I always used drill and screw in extractor in the past, these Boa things look easier to use.


Colin

Offline sparty

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Re: Need help now - exhaust screw stripped.
« Reply #13 on: August 24, 2006, 01:05:04 PM »
Wish I did have a MIG welder, but no, I don't have access.  Great idea however.

I just tried the heat/PB Blaster.  No dice!  I gave myself a nice blister trying to turn that sucker.

I am finished for today, my back is killing me.

Sparty
1972 CB750 K2 Cafe' Style




GO AWAY SNOW AND COLD!  Can you see the Hot Rod wants to run...
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johnny-from-bel

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Re: Need help now - exhaust screw stripped.
« Reply #14 on: August 24, 2006, 01:08:10 PM »
Do you have access to a MIG-welder?

If so, take a nut that´s approximatly the same size as the head of the screw.

Weld it onto the head of the screw through the hole in the nut.

The heat from the weld will help break down the bond between the cylinderhead and the bolt.

Then use the nut to unscrew the bolt...

That´s what I would do  :)


Cheers and good luck!
Daniel

I have done this many times.I have a rod welder I use 1.6 mm rods. It allways works. After you welded on the bold. Use heat, WD40 and plenty of patience. I also have a pneumatic impact wrench. That gets it out every time without ripping the bolt of.

Offline pelicanwheel

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Re: Need help now - exhaust screw stripped.
« Reply #15 on: August 24, 2006, 01:18:08 PM »
This is simple..but has worked for me a time or two:

Based on your photo...get a cheap (harbor freight) 1/4 wide chisel.  It's important that the tip is very sharp.  A screw driver's tip is too blunt.  Position the chisel on the screw so that the flat part is facing to the right and the beveled part is facing left...we're trying to dig into the screw.  If the screw was a clock face, the chisel would be on a line that starts at the clock center (the center of the dish in your case) on up to the "12 o clock" position.  (if this was a regular screw and not phillips and we were using a screwdriver instead of chisel, the position I'm trying to describe would be as if the srewdriver is not center in the slot, but in fact half in and half out).  Tilt the chisel to the right to a 45 degree angle.  Take a hammer and start tapping the chiesel so that the sharp tip digs into the outter circumference of the screw edge.  The combination of the chisel digging in to the screw + you tapping the chiesel in the direction to unsrew the srew + impact of the hammer usually will break free the screw and after tapping a few times (you'll have to reposition the chisel to the new 12 o clock position each time the screw turns.

I've tried to describe this as detailed as I can.  I have never failed to get a screw/bolt out from this technique.

Hope this helps

Pelican

Offline sparty

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Re: Need help now - exhaust screw stripped.
« Reply #16 on: August 24, 2006, 01:22:28 PM »
I just found that I can rent a MIG welder for $39.00 if I must.  I tried the chisel, there isn't enough screw left to bite into.  This is pissing me off!

Thansk for all of your help so far.

Sparty
1972 CB750 K2 Cafe' Style




GO AWAY SNOW AND COLD!  Can you see the Hot Rod wants to run...
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Offline DME

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Re: Need help now - exhaust screw stripped.
« Reply #17 on: August 24, 2006, 02:04:21 PM »
I just found that I can rent a MIG welder for $39.00 if I must.  I tried the chisel, there isn't enough screw left to bite into.  This is pissing me off!

Thansk for all of your help so far.

Sparty

Take the bike to your nearest workshop. They should have a welder and be able to weld that nut on for you, its a five minute job :)

Cheers
Daniel

Offline 750goes

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Re: Need help now - exhaust screw stripped.
« Reply #18 on: August 24, 2006, 02:53:01 PM »
the tip by pelicanwheel is good,

give it a try before you blister your fingers some more, an old screwdriver with a sharpened end like a chisel works the same also, just be patient with the tapping technique and get a good angle on the screw head,

I had a similar problem on mine two days ago installing the headers...got to the last screw and it only went in two turns then stopped....

after cleaning out the thread, trying another screw, more wd40 and lots of swearing, I had to retap the existing thread...
what a pain, but I did not need to helicoil or anything like that..


Offline sparty

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Re: Need help now - exhaust screw stripped.
« Reply #19 on: August 24, 2006, 05:22:00 PM »
I worked on it for another hour this evening.  I sharpened a cold chisel and tried that method.  No luck.  At this point the screw head is really a mess.  I bought a bolt extractor - I have to drill a pilot hole in the screw and then reverse thread the bit into the screw.  I am praying that this will work.  I will again use some PB Blaster and heat.  My garage smells like I was making crystal meth from the Mapp torch.

later,
Sparty
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GO AWAY SNOW AND COLD!  Can you see the Hot Rod wants to run...
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Offline nteek754

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Re: Need help now - exhaust screw stripped.
« Reply #20 on: August 24, 2006, 06:10:48 PM »
Hey  been there done that  if you can drill in the  very middle then try easy out if that dont do it drill a bit bigger take the spigot off and use vise grips as long as you  have enough  screw sticking out good luck it worked for me  Craig in Maine  seven fifty four ever
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Offline 750goes

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Re: Need help now - exhaust screw stripped.
« Reply #21 on: August 24, 2006, 11:38:17 PM »
If you use a bolt extractor - weld something to it, then try and turn it out...

must be really stuck in there - is this the first time you have taken these off -???

Offline sparty

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Re: Need help now - exhaust screw stripped.
« Reply #22 on: August 25, 2006, 03:20:18 AM »
If you use a bolt extractor - weld something to it, then try and turn it out...

must be really stuck in there - is this the first time you have taken these off -???

Yes first time they are off.  The PO really messed the bugger up.

Sparty
1972 CB750 K2 Cafe' Style




GO AWAY SNOW AND COLD!  Can you see the Hot Rod wants to run...
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Offline 750goes

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Re: Need help now - exhaust screw stripped.
« Reply #23 on: August 25, 2006, 02:55:22 PM »
The PO may have used some loctite on the threads...because if it is not turning with all that you have done so far, then I don't envy you in trying to get this out.

keep trying it will happen :)

Offline sparty

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Re: Need help now - exhaust screw stripped.
« Reply #24 on: August 25, 2006, 07:45:15 PM »
Well, it seems that this bugger isn't coming out.  I am now thinking of cutting off the exhaust flange to see if I can get a better bite on the remaining screw head.  So far, every indication of this stuck bolt/screw is lending itself to drill and tap.  What size would/should I tap it if I must?  Do you recommend the use of a Helicoil?

Thanks.

A very frustrated,
Sparty
« Last Edit: August 25, 2006, 08:08:02 PM by sparty »
1972 CB750 K2 Cafe' Style




GO AWAY SNOW AND COLD!  Can you see the Hot Rod wants to run...
“That's thirty minutes away. I'll be there in ten.”