Help! I tightenend a nut too much and now the threads snapped!

Nahom

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Sep 23, 2016
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229
This is the two threads sticking out of the engine which screw into the exhaust pipe. Everytime I rode it the exhaust would jiggle around and one of the nuts would keep coming loose- so I decided to tighten it but this time way too far- and now the story is as title says- what the hell do I do :( I can see about half a centimetre of that snapped thread sticking out from the engine
Is there a way to get it off which doesn't involve taking off the engine? and taking apart? :(
I'm going to use a torque wrench also next time- but I don't now the torque specifications for these motorized bikes...
 


zippinaround

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Aug 4, 2013
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If there's enough sticking out you could grab it with a vice grips if not you could try cut a slot in the bit sticking out and remove with a screw driver , what I usually do is file it flat dot punch the center and drill a hole in it then hammer a good Phillips head into the hole.
 

Nahom

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Sep 23, 2016
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If there's enough sticking out you could grab it with a vice grips if not you could try cut a slot in the bit sticking out and remove with a screw driver , what I usually do is file it flat dot punch the center and drill a hole in it then hammer a good Phillips head into the hole.
Ok, I'll try that thanks- but when I get it out- I need to put a new one in.
Can I get a new screw of the same thread size then when I am done screwing in with the head of the screw sticking out then I can cut the head of the screw leaving just the head just the like the other side?
Also my issue is how do I stop this happening again?- I am a little ham fisted and my intuitive feel of torque is not very good at all...
 
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Steve Best

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Sep 22, 2012
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I'm going to use a torque wrench also next time- but I don't now the torque specifications for these motorized bikes...
Ahh, famous words. Closing the gate AFTER the horse has escaped. I've been there myself.
You can work on it "in frame" but these engines are so easy to remove, I'd be inclined to do so.
If you mess it up, you will be removing the engine.

Plug the exhaust port with a rag or paper to keep any metal bit out.
Heat the area with a propane or butane torch, especially if you used Locktite.
Soak it down with a good penetrating oil. WD40 is NOT a good penetrating oil.
Grip the 2 threads with a sharp NEW vise grip plier and spin it out. Dull pliers will slip.
If it gives any resistance, work it back and forth to free it up. Spin it out.
If you don't have to resort to drilling, you are fine with the same size stud.

If you have to drill, you need to get the first hole perfectly centered, or all will be a mess.
Forget the Philips, get an extractor bit. The extractor bit will work where the Philips bit fails.
If you can extract the stud, you can use the same size replacement.

As for torque, look up in the charts but remember to use the value for aluminum, ie:
http://www.allpar.com/fix/body/fasteners.html
http://www.southwestairsports.com/ppgtechinfo/general/torque-values.pdf
Most torque charts assume you are threading into steel or cast iron and give too high a value.
 

Nahom

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Sep 23, 2016
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What penetrating oil would you use? I always thought WD40 was the go-to. What's wrong with it?
 

Steve Best

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Sep 22, 2012
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Kroil is one of my favouites, PB-Blaster or just about anything clearly labeled "Penetrating Oil" as the first use.
 

butre

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Dec 2, 2013
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WD40 works in a pinch but a mix of acetone and transmission fluid is my preference for penetrating oil.

to prevent this happening again, use the exhaust strap that came with your kit.
 

Nahom

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Sep 23, 2016
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Ok I didn't know about this: I can see two items which are candidates to be this saviour exhaust strap: I've included them in the pics
Which of the two is it please and do you have any pics of how this is used in practice?

Edit: If one of the pics is the exhaust strap what is the other pic?
 

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KCvale

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Using tools and working with mechanical things is not for everyone.
In some cases however it is like beating a dead horse...



It's easy to combat ignorance with education, but there just isn't any easy way to combat... Umm, what should I call this to be politically correct?
Silly? That work for you Nathan?

If you can't use a tool, I suggest you stay away from anything requiring you know how to use one, and that includes a simple wrench, hence a motorized bike.

When you screw up and break off a bolt, a hand drill, tiny drill bit, and an Easy Out drill bit makes things easier, just did a repair for a guy last week so it's fresh on my mind as it wasn't one of my builds, but I know how to get a broken bolt out even if it breaks with nothing to grab.

My best advice for you Nathan?
Cut you losses and quit while you are only a little behind as it is apparent to me you have no skills at all.

Hey, just my option, I could be completely wrong, feel free to post the next thing you can't do right, and the next, maybe someone else will waste their time on you but I'm done.
 
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