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How do you rebuild a crankshaft ?

6967 Views 6 Replies 2 Participants Last post by  PistonHed
I just bought a used and abused bike looks great but the engine was noisy. After tearing down the engine I found it needs the rod and piston and rings replaced. I have been told I can replace the crank pin and bearing instead of replacing the crank with a rebuilt unit I know this would be more work but I have a fairly well equiped shop and would like to try this if anyone knows how. Any help on this subject would be appreciated.
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We re-build cranks ... You need a good press , trueing stand (V block type) , inside & outside micrometers , dial gauge & magnetic base , feeler gauges , and a good brass hammer ... You have to draw a picture of the crank and measure and write down all the measurements like between the crank weights , the measurement outside the weights , dial gauge both ends before dis-assembly to check trueness before it is pressed apart ..
I have all that stuff but the V blocks. Are they used to support the crank?And what is the brass hammer for? Could you go into a little more detail?
The V block type stand is to hold the crank while measuring with dial gage .. The brass hammer is for fine tuning to get the crank as true as possible ..

Here is a couple of pics:

Good 2lb brass hammer ..

Trueing stand..

1/4" , 3/8" , and 1/2" plates to press the crank apart ...

An old crank that was pressed apart for the rod..

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Ok I think I see how it works. I can make a stand like that one.Then I just set the crank up there put the dial indicator on it spin it to make sure its straight.Take some measurements press it apart put my new stuff in press it back together set it on that stand and whack it with the hammer till it runs straight again.I think I can do this. Will let you know how it turns out.Thanks for all the help. Turned wrenches on cars seems like forever just starting to learn bikes.
It's not hard to do ... Here is a couple of pictures of a crank in the press ..

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Was waiting on parts and was real busy over the holiday.Did not have a brass hammer but I had a dead blow hammer.Built a stand its kinda crude but it got the job done.Took the measurments pressed it apart then lined it up by eye and pressed it back together.I put it on the stand spun it checked it with the dial indicator.I whacked it with the hammer like you said to fine tune it.Took a long time to true it up me being a rookie and all but I got it.Will install it and see what happens Thanks for the help Honda Mechanic!
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