Rod bearing play???

moto9

Silver Level Site Supporter
Has anyone noticed excessive play in the crankshaft rod bearing?
I was adding a FWW and noticed that the the rod bearing seemed to have a fair bit of up and down play in it.
I pulled the pipe and put the piston at BDC place my finger on the top of the piston and rolled the crank back and forth...I could feel some play without the piston moving.
The bike has only 46 hours on it,, ARGGG
What do you guys think??
TKS
 
If it a newer bike, 04-05ish, it has a roller bearing on the ignition side and some play is expected.
 
If it a newer bike, 04-05ish, it has a roller bearing on the ignition side and some play is expected.

Sorry, it's an 08 EC 300
The main bearings seem tight, I feel the play in the connection rod bearing...is that normal???
 
The worst case for rod/bearing/crank pin wear is at or just beforeTDC, as that is where the ignition fires and load is greatest. This advice is from Les, who has seen a lot of motors apart in his time.

If its really bad, I would expect it to knock. Is it noisy?
 
Have you had anyone else ride the bike and listen for a bad bearing sound? If you are really sure that what you feel is movement in the rod bearing you'll probably want to pull the top end and actually grab hold of the rod to check it. Have someone else feel it also. Your main bearings on the crank ends may have a little slop which can make things confusing. It seems unlikely for a brg. failure w/ only 46hrs. One thing to keep in mind is that at BDC the crank will rotate w/ very little piston movement compared to 90 degrees away from BDC when you'll have the most piston movement from every degree of rotation.
 
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Have you had anyone else ride the bike and listen for a bad bearing sound? If you are really sure that what you feel is movement in the rod bearing you'll probably want to pull the top end and actually grab hold of the rod to check it. Have someone else feel it also. Your main bearings on the crank ends may have a little slop which can make things confusing. It seems unlikely for a brg. failure w/ only 46hrs. One thing to keep in mind is that at BDC the crank will rotate w/ very little piston movement compared to 90 degrees away from BDC when you'll have the most piston movement from every degree of rotation.

I don't hear any knock when it's running, I'll keep an ear on the engine and if I start to hear it get noiser or a knock, I'll pull it apart.
TKS
 
If your bottom end is bad, you'll know. If you can't hear it, it's probably fine. If you're deaf, or if you're not in tune to your bike's sound, it'll tell you when it's really bad by making loud hideous noises.:D
 
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