Question on Play in crankshaft ? yz250
Posted 08 December 2007 - 11:31 PM
Should there be any play in the crank ? There is no up down play but i can push or pull the crank from side to side about 1/8th to 1/16th of an inch.
A rattling or rumbling noise just started from the bottom end.
The bike runs wells, shifts well, just new noise.
We pulled the right engine cover and can't anything obvious as to where the noise is coming from. Power valve and water pump seem fine. Noise is there in neutral and also when in gear, either with clutch in or out.
any help is appreciated. Thanks
Posted 09 December 2007 - 05:46 AM
Also, when you are checking the rod for play (up and down) you need to slowly rotate the crank and feel at every point. The lower rod bearing once went bad on my KX250. I pulled the cylinder, checked the rod, and figured that everything was OK. It wasn't. The sound continued, so I pulled the cylinder again. I found that there was only play at one small point in the rotation.
Posted 09 December 2007 - 06:59 AM
Posted 09 December 2007 - 12:12 PM
Is the side to side play that you are describing in the rod, or the crankshaft?
Some side to side play is normal in the rod, but there should be no play in the crankshaft.
Posted 09 December 2007 - 12:55 PM
If I move either the flywheel or the main gear on the right side of the crank, I can move it slightly from right to left, but doesn't seem to have any up down movement.
the noise was a knock like something was bouncing around, but not a consistant knock. I think it could be the crank shaft bouncing back and forth a little.
So, just to confirm that there should be NO play up down, right left.
Thanks for the replies.
Posted 09 December 2007 - 02:04 PM
Posted 09 December 2007 - 02:50 PM
im starting to get this to. sounds like a bolt bouncing around, its not down on power starts easy tons of compression, going to check it out this week, doesnt make any since only 20hours on it, and using 24:1 oil using castrol 927 so its getting plenty of oil