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Cam Chain & Top Idler Query

Posted: Tue Jan 14, 2020 6:22 pm
Author: Tonto
Chaps, apologies my spannering skills are a bit limited and any advice would be appreciated.
Was checking valve clearances today on my Z1000A1 project - bike is still on my ramp but starts and runs fine with no noises or rattles etc (meant to be low miles but no guarantees).
A couple of inlet clearances were tight, but more worryingly whilst rotating the crank I noticed that the cam chain was not at a constant tension and appeared to have a slack spot. I dismantled and checked the tensioner which appeared to be functionng Ok. I then whipped off the top idler gear, the gear was hardly worn but felt loose on its shaft (as if its needle rollers were failing).
I was going to replace the cam chain and top idler, or get he bike looked at by someone who knows what they are doing :blush - but before doing either is there something I am missing and should be checking out ?

The bike's been running strongly for a few workshop sessions without any drama, so reasonably I did not think there were major problems: maybe I am being delusional.

Cheers Tim

Re: Cam Chain & Top Idler Query

Posted: Tue Jan 14, 2020 7:34 pm
Author: chrisu
you did have the bike at TDC before you removed anything didn't you ?

Re: Cam Chain & Top Idler Query

Posted: Tue Jan 14, 2020 7:42 pm
Author: zed1015
It is very unlikely that the needle bearing has failed but the rubber that is sandwiched between the outer sprocket ring and the inner bearing holder degrades over time and becomes detached .
This is what may have happened to yours .
It is a common occurance and best replaced with a solid Liska type.

Re: Cam Chain & Top Idler Query

Posted: Wed Jan 15, 2020 12:00 pm
Author: Tonto
Thanks, will acquire / fit a new one.
Chrisu - yes crank was at TDC, but since then I think my ineptitude may have caused me a new issue :-(

Re: Cam Chain & Top Idler Query

Posted: Wed Jan 15, 2020 12:02 pm
Author: Pigford
Tonto wrote:Thanks, will acquire / fit a new one.
Chrisu - yes crank was at TDC, but since then I think my ineptitude may have caused me a new issue :-(



You ain't bent some valves now, have you?

Been there and done that whilst adjusting auto-tensioner....... not once, but twice in the last 30yrs :roll: