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crank shaft failure? (video inside)


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long story short 5th gear started making grinding noises (sounded like metal on metal). first to second was extremely difficult and notchy. bike was surging as well. decided to take apart the bike (stopped short of removing the motor and splitting the case), noticed that the countershaft sprocket was lose and that the clutch basket was making this noise. based on other youtube videos im assuming my crank shaft bearing is done?

thanks in advance for any advice.

 

 

Edited by sumo zed
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1 hour ago, Erik Marquez said:

The clutch basket is not connected directly to the crank
 

The back lash you are showing is likely normal but not really confirmed or denied by twisting the basket back and forth 

Wow didn’t expect a reply from the man himself. Reassuring to hear that. I will put her back together and temporarily tighten the counter shaft sprocket (I have all the replacement parts and chain ready to be installed) to see if the symptoms described have been alleviated. 

If the bottom crank shaft bearing is gone as I suspect, are there any major signs or tests that would indicate a possible failure (aside from splitting the case)?

 

 

 

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10 hours ago, sumo zed said:

If the bottom crank shaft bearing is gone as I suspect, are there any major signs or tests that would indicate a possible failure (aside from splitting the case)?

"bottom crank shaft bearing"
Are you talking about the lower rod bearing? or the crank case crank bearings?

There is now "test procedure" for crank bearings, its kind of a feel and look deal.
If your talking about the crank/ rod lower bearing there is a test procedure, the head and cylinder need to be off..And you will need a dial indicator  

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You can check the rod bearings through the sparkplug hole to an extent . Rotating the crank by the flywheel nut till the piston hit tdc, then going a bit more so the piston is now being pulled down , 1/2" or so is enough. Now a brass rod (or aluminum) down the sparkplug hole to the top of piston . Hold the flywheel solid you push down on the brass rod , you can put an indicator on the top of the rod to watch movement(not extremely accurate for very small movements). Usually if the rod bearing is bad you'll be able to feel the piston move down before stopping and trying to turn the crank. That free movement is clearances in the rod bearings . It's a quick "general "bearing check without tearing apart , if done with care and repeatedly to verify , can be quite good .  By the sounds of this symptoms , i'd look more at the 2nd gear bushing or the bushing under the clutch(outer basket) . I've seen several DR650 clutch bushings ground down from lack of oil , even had one Yamaha that seized up tight when the motor shut down at 60mph in traffic so the guy had to let it coast till he could get off the side of the road, by then the clutch was solid.

 

 

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Edited by jjktmrider
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