rod play? how much is a bad thing?

[yamaha04]

how much is a bad thing. i just tore my motor apart today for the winter to freshin it up to find a hole in my head witch i think in a yamaha defect and my one piston is alittle sloppy in the cylinder. also my rods have some side to side play but no up and down i think this is normal i mean theres not much. what do you guys think?

[Bansh-eman]

how much is a bad thing. i just tore my motor apart today for the winter to freshin it up to find a hole in my head witch i think in a yamaha defect and my one piston is alittle sloppy in the cylinder. also my rods have some side to side play but no up and down i think this is normal i mean theres not much. what do you guys think?

if you have any play you need to get it rebuilt... on a part that is spinning at 10,000 rpm's the slightest play is intensified tremendously.

[bansheefreak]

ive heard side to side play isnt bad as long as it not alot but up and down is real bad if any..... but this is what i have heard no pro here...

[yamaha04]

yeah the up and down is probably really bad but mines ok that way the hole side to side thing has me wondering i dont think its that much of a gap they down't move much but maybe i will just send the crank away with my heads when they go to Jeff @ FAST.

Edited December 3, 2006 by yamaha04

[Animalman294]

Ask Jeff about it, he'll tell you if it's too much............... :beer:

[kubiac3]

Up and down should have no play, side to side play is ok to a certain tolerance. In the ol clymers manual i think it said 2mm of play side to side is the max. My brand new crank from vitos had half a mm play in it out of the box.

[JaysonP]

yea i agree, because if you have up and down play, that could end up in a piston thru your heads, EEK!

 

side-to-side is fine(with in tollerance) depending on the matereal of the rod and how it is treated(brand)

[BigRed350x]

Man, I remember my old 87 had crazy side to side play and I ran the piss out of it. Thinking back now... I never would have run that crank now-a-days. I was a poor high school kid though. Ha Ha! Probably helped contribute to my engine blowing up every time i rode the stupid thing. Ha Ha!

 

I've used cranks in the past that had a little bit of side to side play. (like under .100") one way. With no problems. I don't know an official spec though. Side to side is ok as long as its very minimal, but any up and down play... scrap it!