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Messed up Flywheel Threads

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I have a XR100 that i was in the process of removing the flywheel, when I decided to use a method I thought would work. Well it did not and I damaged my crank shaft threads.I ended up ordering a puller and that worked great, but when I tried putting the flywheel nut on, it would not even attempt to bolt on. I have worked on it with a dremel some and it has not worked. Without a thread chaser or die, how could I fix this.

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A Dremel on threads?  😱

There is a thing called a thread-file.  THAT is the only thing that will "fix" your threads.  Google it.

Leave the power tools alone next time.  😐

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Well, as you've already figured out the hard way, you should've bought the puller before you tried your ineffective, and thread damaging idea. 

WTF were you thinking using a dremel on an expensive part like that??! (Without being proficient in doing such a task) 

You should've left it alone until you could've gotten to the tool store and bought the proper thread chaser. 

A triangle file has worked for me fixing threads, or as another stated a thread file, or yes, the proper thread die/chaser which isn't expensive. 

To put it into perspective, 

Thread die $5-15 probably, new crank $240 on Partzilla.com. Hope you're able to get it fixed

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thanks for the responses. what I have been doing is using a bolt with the same threads as the crankshaft and lining them up, the tapping on the bolt to kind of re align the threads. If that doesnt work ill go with a die. does anybody have a link for a cheap one?

Edited by Judah Gardner

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58 minutes ago, Judah Gardner said:

thanks for the responses. what I have been doing is using a bolt with the same threads as the crankshaft and lining them up, the tapping on the bolt to kind of re align the threads. If that doesnt work ill go with a die. does anybody have a link for a cheap one?

STOP!  Step away from the threads!  😡

The only way to fix damaged threads is via a hardened tool, either a file or die or tap if it is an internal thread.  Trying to jam an unhardened bolt into damaged threads is a recipe for disaster as the two metals will jam together and probably damage both even further.

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This is for an external or male thread:

Measure OD of the thread - using a pair of calipers.  You will need this measurement in mm because it is a Japanese bike.

Then measure the thread pitch.  For metric threads this will be the distance from the peak of one thread to the peak of the thread beside it in mm.  Normally they will be in .25mm increments.  e.g.. 1.0mm or 1.25mm or 1.5mm etc.  The smaller threads can be in .1mm increments though.  

A better method is via a thread pitch gauge but I doubt you have one of those.

 

Thread-Pitch.jpg

Thread sizes typically have specific or standard pitches associated with them.  This chart gives the most common sizes for metric threads.  

As an example you will never find a 20mm bolt with a 0.5mm thread pitch.

thread-pitch-metric-2.png

Edited by CDNSXV

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