Little man with a hammer Harley Twin Cam Discuss Little man with a hammer in the Motorcycles forums; Here's one for ya,gang. 99 Road King came into shop for a top end noise,we both road tested the bike & reached the same conclusion:a broken valve spring.Pulled the rockers,springs ...

[aceharleywrench]

Here's one for ya,gang.
99 Road King came into shop for a top end noise,we both road tested the bike & reached the same conclusion:a broken valve spring.Pulled the rockers,springs are fine.Pulled the heads & cylinders found scoring on pistons,so deep had to go to second oversize to get the cylinders to clean up,problem solved,right?Nope,same noise!Checked primary & cam case,everything good.As I was preparing to yank the cases from the frame I decided to re-check pinion shaft runout (checked when we did cams a few months ago) was within acceptable limits (.0015) but as I'm turning crank over for the tenth or so rotation I feel something odd,rock the crank back & forth a few times & there it was.The rod bearings are junk!!!It took that many rotations of the crank to get the bearings to rotate to where you could feel they were bad.Normally big end bearings have a much deeper sound,this sounded for all the world like a valve spring.Just a heads up,not much fools me,but this one had me scratching my head.

[unclepsycho]

Glad you caught it before re-assembly again... good job!

amazing machines we ride huh.....

[shovelmike]

Good job there Ace.

[BluesFan]

Good catch. Persistence is key, When I listen to a machine with my ultrasonic probe I listen for a good long time, Amazing what you can hear.

I can hear ball and race defects pretty easy.

It is also possible to localize the noise. I do wonder what I would hear if I listened to my engine.

A bad one would be super cool to listen to.

It makes my day when I call a bad one and then see it later.