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Author Topic: how to split a pressed together crank to remove the rod....xl125  (Read 2560 times)

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Offline jaguar

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how to split a pressed together crank to remove the rod....xl125
« on: July 15, 2010, 12:25:37 PM »
im trying to find out the best way to remove the rod from a XX125 honda motor.
i know that its pressed together.

thanks for any help
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Offline scottly

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Re: how to split a pressed together crank to remove the rod....xl125
« Reply #1 on: July 15, 2010, 07:23:26 PM »
How I did it was take it to a shop with the proper tools and expertise. Putting it back together and getting it to run true is much more difficult, by the way.
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Offline scunny

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Re: how to split a pressed together crank to remove the rod....xl125
« Reply #2 on: July 15, 2010, 07:33:06 PM »
+1  had to do that to my GS1000, broke a conrod and took the new rod and crank to a local firm who have the gear. somethings are best left to others
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Offline MRieck

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Re: how to split a pressed together crank to remove the rod....xl125
« Reply #3 on: July 15, 2010, 07:58:15 PM »
Quote from: scunny on July 15, 2010, 07:33:06 PM
+1  had to do that to my GS1000, broke a conrod and took the new rod and crank to a local firm who have the gear. somethings are best left to others
Very good advice
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Offline bryanj

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Re: how to split a pressed together crank to remove the rod....xl125
« Reply #4 on: July 16, 2010, 06:20:37 AM »
About a 50 ton press from memory
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Offline 754

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Re: how to split a pressed together crank to remove the rod....xl125
« Reply #5 on: July 16, 2010, 08:07:01 AM »
I had a buddy that would use my press and do them.. Main trick is to scribe them first.

 I am thinking, 20 or 25 tons will do most..

 He used what he called a CAN to do them, and we built a few. Basically a heavy tube with notch  for the rod, and a plate to support the flywheel halves, while pressing pin out or in. More than one cylinder, it gets more involved.
 
 Usually pressing involves shims to maintain side clearance, and assembly must be trued after pressing together. The key here is using the scribe lines, and a square to line up the bits on reassembly... one time he got it to 2 or 3 thou, just pressing it together.. very little truing on that one.
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Offline simon#42

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Re: how to split a pressed together crank to remove the rod....xl125
« Reply #6 on: July 16, 2010, 10:43:14 AM »
i rebuild two stroke racing cranks as part of my business ,i use a 20 ton press and have several boxes of ' usefully shaped '
pieces of metal which i use for pressing cranks apart  .  the hard bit is getting them apart ,and back together perfectly square [ otherwise you will damage the flywheels ] truing the crank is pretty straight forward . if i where you i would take it to someone local who has a good reputation [ someone that does two stroke motocrossers might be a good place to look ], its not an expensive job and it might take you a few ruined cranks to get the hang of it 
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Offline jaguar

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Re: how to split a pressed together crank to remove the rod....xl125
« Reply #7 on: July 16, 2010, 01:03:21 PM »
my goal is to take the rod off so i can model on for a CAD/cnc project that im trying to do.

my plan is to split the crank and re-install the new rod and pin.
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