HELP PLEASE!

[cboling]

I was trying to clean out some threads today on my exhaust. The previous owner or someone used a standard bolt in place of the 8mm x 1.25 bolt. I went to ACE and grabbed a tap (8mm) and everything was going well on the first hole when *SNAP* the stupid thing broke off in the hole. Far enough that I can't get anything in there to get it to back out. Any ideas? I don't have a welder and there's not anything sticking up to weld to. I have tapped on it lightly trying to get it to break up but don't think that is going to work. I am open for any DIY suggestions if anyone has any.

Thanks,
CB

[joshr08]

go back to ace and get a screw extractor and the drill bit that it calls for aka an easy out.  use a center punch to make it for drilling and stay to the inside other wise you will get into the threads and have to helicoil the hole.

[AccidentalF]

+1 what he said.  But be prepared....those taps are some pretty hard stuff.  You might want to grab multiples of whatever drill bit you are using so you can swap out the dull ones.  There will be many.  In the future, try cutting oil and a progressive back-and-forth technique for tapping (a kind of 2 steps in, 1 step back thing method)

How much of the extractor is broken off?  If its not too much, you can try a dremel with a carbide cutting bit and simply grind it out.  Sounds awful, and it is, as well as messy and noisy.
But it works sometimes where drill bits wont.  Just dont grind much of the surrounding aluminum or it will enlarge the hole too far for re-tapping.

[DoD#i]

IME you won't be drilling a tap unless you are using a carbide bit - and then you have decent odds of breaking that off - carbide drills are brittle. Taps are at least as hard as drills, if not harder.

Using a left hand drill bit in a drill that runs in reverse (so a left hand drill bit can work) might help a bit - you have some odds of nudging the thing back out as you drill.

But you might just be in the territory where "stop now and call on competent local help before you are replacing the head you've REALLY boogered up" is the right response.

[GeeP]

Start here:

http://victornet.com/report/Extractors-Tap/502.html

DO NOT attempt to drill it out freehand.  Doing so will likely damage the threads, possibly beyond repair.  If you can't get it out with a tap extractor of the appropriate size, find an 8mm drill bushing and thread that into the hole until it bottoms out on the tap.  THEN, drill a center hole though the tap with a carbide drill.  Once center drilled, you can drill slightly smaller than the minor diameter of the 8mm external thread and spiral out the remainder with a pick.

If there are fewer than 3-4 threads showing in the hole, the head will have to come off.

[cboling]

EDIT: Thanks Geep. I may just try those extractors. That may just do the trick! If not, then I will go for the option below.

Well, I just spent the past couple of hours pulling the top end. Is it normal to have to pry at the copper washers that are under the cap nuts? Those were a real pain. I was very careful but even with that, there are some marks around that area. When I go to re-install, should I simply use stainless and re-torque properly? I am sure I will find that out when I read the Clymer manual further.

Anyway, I think I am going to save aggravation and money and take it to the local shop and have them get the piece out and re-tap the holes properly for me. Hopefully, that won't cost much.

Any other ideas while I have the head off? Should I contemplate having any work done to the head / cylinders for better performance / power? Not trying to spend a fortune as I only paid $400 for it in the first place.

Here it is as I bought it:
http://bolingfordollars.net/Cycle_Parts/p5280001-3.jpg
http://bolingfordollars.net/Cycle_Parts/p5280001.jpg
http://bolingfordollars.net/Cycle_Parts/p5280002.jpg
http://bolingfordollars.net/Cycle_Parts/p5280003.jpg
http://bolingfordollars.net/Cycle_Parts/p5310011.jpg

The apartment complex didn't take too kindly to it sitting on the crate so I have had to put the front end back on for now and keep the tarp over it. I am waiting on front seals to come so I can get that out of the way. I am hopefully going to have it running in a couple more weeks or less. So, I will keep everyone updated.

Thanks,
CB

[cboling]

Update: I ordered a 5/16" 4 flute extractor from MSC online. Got it this afternoon and within 5 minutes, was able to undo the disaster. Now if I can carefully continue to re-tap the holes to 8mm.

[GeeP]

Good to hear!  

A good quality tap, little WD-40, a light touch, and backing the tap out a turn every couple turns should prevent any further tap extraction practice.  

Don't over-torque the mounting bolts either!

[DoD#i]

1/2 turn forward, 1/4 turn back - not several turns forward ever (when cutting). Back the tap all the way out to clear chips from time to time.

Lube (cutting oil - motor oil does fine in a pinch) a bit more serious than WD-40 (which is really not lube at all.)

[kml.krk]

am I crazy or is your front tire mounted backwards?

I thought that tire tread is supposed to redirect water and dirt from the center of the tire to the outside,
and it looks like it would do exactly opposite in your set up 

I am talking about this picture: http://bolingfordollars.net/Cycle_Parts/p5280001.jpg

[JB848]

It always blows my mind the things that people notice that have nothing to do with the original post topic. But that is correct that tire is mounted backwards but looking at that picture I think that is the least of his worries at this point!

I'd say you are very lucky to have gotten that tap out as others have warned the dangers of doing that. The question is how in the world did you break the tap off in the first place!

[GeeP]

1/2 turn forward, 1/4 turn back - not several turns forward ever (when cutting). Back the tap all the way out to clear chips from time to time.

Lube (cutting oil - motor oil does fine in a pinch) a bit more serious than WD-40 (which is really not lube at all.)

Not always...  He's not cutting new threads, thus the gullets won't fill up so quickly.  No need to break the chip as often.  I always go by feel.

For Aluminum, WD-40 is an excellent tapping lube.  It's also good for sawing, turning, and milling.  The only reason for using any lube with aluminum is to prevent it from sticking to the tool, which is a hazard with "gummy" casting alloys.

EDIT:

His tire isn't necessarily backwards.  The Roadtec Z6 on my SV looks the same, and the rotation arrow points in the correct direction. 

[the mole]

You were very lucky that tap came out!
+1 on the WD40, kerosene is also good for aluminium.

[cboling]

I'm not sure about the tire. I will look at that more closely. I bought this bike broken down so I haven't even tried to ride it yet. It's more than17 years since I have ridden a bike and this is my "new" starter bike. I will look at that tire just out of curiosity but I have new / used tires on the way. I wouldn't be surprised if it was on backwards just looking at the overall cosmetic condition / previous upkeep.

As for the tap breaking, I am not sure why it broke. I didn't use lubrication the first time so I am sure that was the root cause but the new tap I have looks like the teeth are chipping off and I am using a spray lubricant. Not sure why this is but this time around, I am going very very slowly and carefully. It actually broke 1/4" from the tip when it broke so I am not sure why. It was about 1/2" into the hole.

I am definitely trying to go carefully because I do not want to repeat that again. Thanks to all for the help.

[cboling]

Can anyone guess what this is? 






I only wish I wasn't so smart. I just knew within my bones I could tap a helicoil!? 

All kidding aside, let this be a lesson to you.....er......me, always check first to see if the hole has already been repaired. If it has that much resistance trying to do a simple re-thread, chances are, it already has. DOH! (I should've left well enough alone.) Well, at least it's not totally destroyed.

[GeeP]

Yeah, heli-coils aren't known for their machinability.   

Sounds like somebody put an imperial heli-coil into a metric bike.  I would replace with same.   

[cboling]

Okay, I got the 3 old helicoils out, and went to pepboys and picked up some 8mm and 5/16 just in case I had to put 5/16 back in. Luckily enough, the holes were not drilled large (for the 5/16) so I was able to re-tap with a 10mm  / 1.25 and put in the 8mm. Life is now good for the obsessive compulsive.

Now just to get all the painting finished and start putting it back together.

[DoD#i]

and start putting it back together.

Use anti-seize; or there will be a next time.

[JB848]

I guess because I was raised around VW beetles and wrenched on them a lot I developed a feel for sparks plugs and never really had any problems with them and aluminum heads. My method always was to use my finger tips to start them until I couldn't turn them any more, and then like I said and someone else concurred with above using only one hand and not your whole arm you just can't over tighten them.

Also as you know we all love pictures but do they have to be so huge? Especially when most of the picture is background? 640X480 is more then enough and page reader friendly