flywheel movement

[CR69r]

Over the winter i noticed enough flywheel movement to make a tap when i pulled up on it. Although the bike ran fine, i had the crank bearings replaced. when i picked up the motor the movement was gone. now just out of curiosity i checked it after 13 hours of riding time. It moves again, but not enough to make as loud a knock like last time. Again, the wierd thing is the bike is running perfect all along. You would expect a questionable big end bearing to display some symptoms. I took it back to the shop that did it and the owner dribbled something about C3 clearance and told me not to worry about it. Is this some strange honda phenomenom, where its OK for this flywheel to move, or do i have something going on here that no ones telling me about?

 

[jmics19067]

there has to be some clearance so the oil can do its job but it is not usually noticable. for me usually the clicky feel doesn't happen until.005".
I don't know what the clearances should be for a crank main bearing on your bike but..... wheel bearings on a tractor trailer should be .002".

to little for me to "feel" any movement but some guys can look at a 2X4 and say it 10 ft long when I need to use a tape measure.

As long as the bike doesnt wipe out the main seals and the bearing isn't locked up it will appear to run fine. There is nothing that is actually preventing the engine from running proper but there will be extreme possiblity that it will go south in one shot. IE you can actually hear the bearings growl but it still runs so you give it a ride, the crank seal gives out making it run lean melting the top end and the mains start spinning in the cases causing lots of cost.

If you dial indicate the actual movement and know the bearing numbers you probably could go to a machine shop or a bearing supply house and get the actual running clearances and out of limit clearances.