Author Topic: Snapped a bolt in my 650 head-$100 if you can fix in Brooklyn  (Read 3160 times)

0 Members and 1 Guest are viewing this topic.

Offline jeepster

  • Hot Shot
  • ***
  • Posts: 292
Snapped a bolt in my 650 head-$100 if you can fix in Brooklyn
« on: October 25, 2009, 02:31:03 PM »
A bolt snapped of in my cylinder head. It's basically flush:



I'm going to assume that I'll need a new cylinder head gasket as well...which I can buy.

I already have the head cover off, and can handle the carbs and exhaust. I don't feel like I have the skills to take the head off though with out doing more serious damage though. So, yeah I need the head taken off, bolt extracted and re-helicoiled, then need to get the cylinder head back on.  I live in Brooklyn.

Anybody interested? If not, do you know anyone who can do this at my place? I can't justify spending any $$ at all right now, but I REALLY can't justify spending $100 just to have my bike towed to the shop.
« Last Edit: October 25, 2009, 09:10:55 PM by jeepster »
"An ounce of prevention is worth more if you break it up into nickel bags."

Offline Kevin400F

  • Hot Shot
  • ***
  • Posts: 600
Re: $100 to help with my bike
« Reply #1 on: October 25, 2009, 03:17:34 PM »
Did you find it broken compliments of a previous owner, or did you snap it yourself?  If it broke during tightening, you might be amazed by how easily the remains might unscrew out of the head using a simple screw extractor, or even cutting a slot for a straight screwdriver bit with a Dremel.
 
If the threads are siezed and it broke when you were attempting to loosen it, then you're probably right that it will need to be drilled out.  Whether or not that demands head removal depends on how careful/patient you are.  If it were mine, I'd pack the area off with rags, grease, etc and give it a go right there in place.  Nothing ventured, nothing gained.....if you can't get it done in place, then pull the head.

Offline tomkimberly

  • Expert
  • ****
  • Posts: 1,113
Re: $100 to help with my bike
« Reply #2 on: October 25, 2009, 03:17:40 PM »
Looks like to me you have enough room to use a left hand drill bit and a hand drill. Drill a hole and if you are real lucky, the screw will just back out. If is does not come out, after drilling the hole, it should come out with an easy out. If the threads are messed up afterwords, install a heli-coil. I see no reason to remove the head. Make sure to cover the cam area with some newspaper and masking tape so teh chips do not get into the engine.

Remember, use a left hand drill bit!


Tom


Offline jeepster

  • Hot Shot
  • ***
  • Posts: 292
Re: $100 to help with my bike
« Reply #3 on: October 25, 2009, 04:08:19 PM »
Did you find it broken compliments of a previous owner, or did you snap it yourself?  If it broke during tightening, you might be amazed by how easily the remains might unscrew out of the head using a simple screw extractor, or even cutting a slot for a straight screwdriver bit with a Dremel.
 
If the threads are siezed and it broke when you were attempting to loosen it, then you're probably right that it will need to be drilled out.  Whether or not that demands head removal depends on how careful/patient you are.  If it were mine, I'd pack the area off with rags, grease, etc and give it a go right there in place.  Nothing ventured, nothing gained.....if you can't get it done in place, then pull the head.

I wish I could blame the PO, but I broke it all by myself... :P
This hole is helicoiled, but I never drilled it out because the threads were missing. I basically just tapped new threads and installed the helicoil. The helicoil went in very tight towards the bottom and as a result the bolt was tight in the helicoil making it impossible to torque correctly. so...I think the bolt is in there pretty damn tight. Do you think it's worth it to mess around with the reverse drill bit? I'm thinking that a good bolt extractor will cost about $100, which is why I thought I would find someone who can do this quasi- professionally.



"An ounce of prevention is worth more if you break it up into nickel bags."

Offline jeepster

  • Hot Shot
  • ***
  • Posts: 292
Re: $100 to help with my bike
« Reply #4 on: October 25, 2009, 04:27:20 PM »
Oh yeah, it's a 6mm bolt... so I guess I need what, a 3mm bit? Anyone know?
"An ounce of prevention is worth more if you break it up into nickel bags."

swiffer

  • Guest
Re: $100 to help with my bike
« Reply #5 on: October 25, 2009, 04:41:18 PM »
Hardware stores sell those counter screw bits that you drill in and reverse the whole shank out.Or that maybe what you are thinking.

Offline 333

  • Time for change
  • Really Old Timer ...
  • *******
  • Posts: 7,557
  • Mail List Member #162 - Call me Stan
Re: $100 to help with my bike
« Reply #6 on: October 25, 2009, 06:06:57 PM »
Hardware stores sell those counter screw bits that you drill in and reverse the whole shank out.Or that maybe what you are thinking.

Easy Out.  That's what I know them as.  Use a torch to heat up the block.
Go metric, every inch of the way!

CB350F0  "Scrouching Tiger"
CT70K0    "Sneezing Poodle"

www.alexandriaseaport.org

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,058
Re: $100 to help with my bike
« Reply #7 on: October 25, 2009, 06:28:54 PM »
EZ out does not work well on small stuff, except the Rigid/Snap-On style that has the splined drive pin..used with 1/8 in drill.

 Best case scenario, IF you can make it happen;

Install cover and make a bushing the hole size in the cover, the inside of that bushing will have an 1/8 in hole thru it.

This will guide the 1/8 inch drill as straight as possible.

When you drill , use an 1/8 Left Hand if possible, hopefully that will get it out, if not then try the spline extractor.

 With a bit of luck the helicoil may come out with it.. if not there is a trick to get them out, it should be redone properly..
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline tomkimberly

  • Expert
  • ****
  • Posts: 1,113
Re: $100 to help with my bike
« Reply #8 on: October 25, 2009, 06:55:35 PM »

Offline NickC

  • Hot Shot
  • ***
  • Posts: 703
Re: $100 to help with my bike
« Reply #9 on: October 25, 2009, 07:04:01 PM »
Whatever you do, that involves drilling/metal splinters, I would suggest loading up the space to the left with petroleum jelly to catch slivers....

Offline jeepster

  • Hot Shot
  • ***
  • Posts: 292
Re: $100 to help with my bike
« Reply #10 on: October 25, 2009, 08:08:58 PM »
OK. I think I am going to go buy a left hand drill bit tomorrow and see if I can coax this little bastard out. I think I am going to start the hole with my drill, then use a pair of vice grips once it gets in deep enough to turn. After reading all the advice on here and other threads I am thinking that the odds are not really in my favor that this will work out well.

What if the drill bit breaks in the bolt... obviously then this is not a job I can do in my living room and I have to take off the head and bring it to a machinist. Will a machinist still be able to drill out the bolt if there is a drill bit stuck in there...? Maybe a better idea to just man up and take off the head and have this fixed by a professional with a drill press? Anybody know what this might cost? Is my $100 offer about right?
"An ounce of prevention is worth more if you break it up into nickel bags."

Offline w1sa

  • Hot Shot
  • ***
  • Posts: 444
Re: Snapped a bolt in my 650 head-$100 if you can fix in Brooklyn
« Reply #11 on: October 25, 2009, 10:33:19 PM »
Often the holding torque of a snapped bolt is not nearly as great as the torque that snapped it.

First I'd try a centred hole with a left hand 1/8 drill bit as suggested. Try not to drill thru bottom of existing bolt. If the drilling action itself doesn't move it choose between the splined drive method for EZ out or perhaps use a left handed thread Tapping bit (say 4mm. If the tapping bit action does not turn it, you can then insert a high tensile threaded bolt/screw in the tapped hole and have another go. (assuming you can get left hand tap and bolt locally).
 
If the smaller bolt snaps in the old bolt, a machinist shouldn't have to much extra difficulty removing them both together. 

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,058
Re: Snapped a bolt in my 650 head-$100 if you can fix in Brooklyn
« Reply #12 on: October 26, 2009, 08:25:24 AM »
You may be able to get a drill sleeve made for 20 bux or less.

 Once you are drilled off centre, or break something off, the cost will rise like crazy..

 If you dont think you can get it in the middle, maybe you cant. You need a very sharp punch with fine tip to center a dimple to start drilling. If you have a very thin, pointed punch, you may try a light punch mark near te bolt edge, then hold the punch at an angle, lightly tap and see if it starts turning.. this is where the tiny ball piens..aka gasket hammers, come in handy..
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline ColinMc

  • Expert
  • ****
  • Posts: 1,006
  • There aint no pickle like a super pickle...
Re: Snapped a bolt in my 650 head-$100 if you can fix in Brooklyn
« Reply #13 on: October 26, 2009, 09:03:34 AM »
I'm thinking, if you didn't actually thread the hole BEFORE putting the helicoil in, that should come out fairly easily. Typically you drill, thread, then thread the helicoil threads into the now larger threaded hole.

If you have a very thin, pointed punch, you may try a light punch mark near te bolt edge, then hold the punch at an angle, lightly tap and see if it starts turning.. this is where the tiny ball piens..aka gasket hammers, come in handy..

I'd give this a shot, has worked for me many times in the past. Just make sure you have a good punch, none of that harbor freight crap. This is one of those times when quality tools pay off.
1976 CB750K - Cafe Project...taking forever
1984 Honda MB-5 - MB-8 conversion in process
2001 Ducati 748 - Built 996 motor sleeper

Offline CBGhia

  • Expert
  • ****
  • Posts: 1,347
Re: Snapped a bolt in my 650 head-$100 if you can fix in Brooklyn
« Reply #14 on: October 26, 2009, 09:23:42 AM »
I have to say that I loves me some left handed drill bits.  I cannot tell you the amount of times they have saved me in the past.   A little heat and some Sea Foam Deep Creep might help as well.
CB550 Cafe, GL1000, Buell Ulysses
if you dont trial spin the camshaft in the head and cover you are a novice,with no natural mechanical appitude,destined for destruction.
"The cleaner the dipstick, the closer to God." -Rev. Horton Heat
“Faster, Faster, until the thrill of speed overcomes the fear of death.”  - Hunter S. Thompson

Offline jeepster

  • Hot Shot
  • ***
  • Posts: 292
Re: Snapped a bolt in my 650 head-$100 if you can fix in Brooklyn
« Reply #15 on: October 26, 2009, 10:05:52 AM »
I'm thinking, if you didn't actually thread the hole BEFORE putting the helicoil in, that should come out fairly easily. Typically you drill, thread, then thread the helicoil threads into the now larger threaded hole.

If you have a very thin, pointed punch, you may try a light punch mark near te bolt edge, then hold the punch at an angle, lightly tap and see if it starts turning.. this is where the tiny ball piens..aka gasket hammers, come in handy..

I'd give this a shot, has worked for me many times in the past. Just make sure you have a good punch, none of that harbor freight crap. This is one of those times when quality tools pay off.

I tapped new threads without drilling so I think the hole is just a pube too small. I also used some threadlocker (on the helicoil, not the bolt) to seal the deal. I'm starting to think that the risk of further damage exceeds my DIY skills. Plus from the sound of it, this is going to require a pretty hefty tool investment with a relatively slim chance of success. Luckily I live in an industrial neighborhood so there are plenty of machine shops within pushing distance. I'm going to call around today to see if I can find one who can get the bolt out with the head still on the bike. If not, that's a new head gasket and more then likely my season.
"An ounce of prevention is worth more if you break it up into nickel bags."