After a ride and letting bike set for a few minutes there is a noise on restart. The noise goes away. The noise sounds like a chain without tension. What is it and how what do i do to fix it
* Last updated by: cardoctor61 on 4/21/2012 @ 8:57 PM *
Created on: 04/21/12 08:54 PM
Replies: 9
cardoctor61
Location: Las Vegas Nv
Joined: 04/21/12
Posts: 1
Rook
Joined: 03/28/09
Posts: 20592
RE: hot restart noise
04/21/12 9:34 PM
Interesting you would describe it as such cuz that is prolly exactly what tit is. Is it a rattle on the right side of the engine? That's where the cam chain tensioner is. It often does not keep the timing chain perfectly taught. That is a defining characteristic of a ZX-14. They all do it, some worse than others.
It is usually much better when the engine oil is fresh. It does go away, usually within 15-30 seconds of idling.
An APE manual chain tensioner will stop the rattle. Also heard that a modified ZX-12 CCT works wonders.
DANOZX14
Joined: 10/15/11
Posts: 38
battleaxe
Location:
Joined: 02/09/09
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DANOZX14
Joined: 10/15/11
Posts: 38
Rook
Joined: 03/28/09
Posts: 20592
RE: hot restart noise
04/29/12 12:33 AM
Hey Rook, why does it do it?
The cam chain tensioner is a spring loaded piston. The CCT piston pushes a pivoting glide guide against the cam chain and that is what keeps the cam chain at the proper tension. The CCT piston will always maintain a consistent outward force under the tension of its spring. In this way, it maintains proper cam chain tension as the cam chain stretches with age. There is also no doubt, some range of tension adjustment required to accommodate expansion of the parts as they heat. As you can see, the OEM tensioner adjusts cam chain tension automatically. If the chain gets loose for any reason, the CCT piston pushes forward against it to take up the slack. If the chain becomes tight again such as it may after it contracts from a cool down, the CCT piston will retract in like fashion.
This illustration was meant to show how the CCT piston is set after installed. Ignore the screwdriver and arrows but note the red glide guide, the grey CCT and the blue cam chain.
There is a built in fail safe so that the tensioner piston cannot ever retract too far, allowing the cam chain to slide off of the timing sprockets. The fail safe is that the CCT piston will press out against the cam chain as much as needed to maintain tension but it has a ratchet lock system that prevents it from being pushed back in more than a few millimeters. As the chain stretches with age the OEM CCT pops pushes forward and eventually, it will pop forward enough to lock into the next ratchet stop. Right at that ratchet stop is the ideal place for the OEM CCT to be to keep max safe tension on the cam chain. It is at this point that the cam chain rattle is at its minimum so I might suggest that those of us without cam chain rattle are right at the ratchet stop and those of us with the loudest and longest rattle are pretty much smack in the middle of ratchet stops.
The ribs on the piston you see are the ratchet stops.
Another reason for the rattle is oil breakdown. You will notice the rattle is a lot briefer and prolly not as loud right after an oil change. I believe low viscosity caused by thermal breakdown and combustion contaminants allows much of the oil to run off of the chain when the engine is not running so it is loud when it starts.
How many have the same issue.
Is it milage related?
design?
My 08 will do it after a hot restart.
Do you have a write up on the APE or zx10 mod idea?
how often does the APe need adjustment?
Is it hard to install??
APE. As you can see, it is actually a tiny bit heavier than OEM which IMHO there is no excuse for but ....just a fraction of a gram
* Last updated by: Rook on 4/29/2012 @ 12:44 AM *
Rook
Joined: 03/28/09
Posts: 20592
RE: hot restart noise
04/29/12 12:50 AM
One complaint I have heard about APEs is that they may leak a bit. If you install, might be best to buy a new O-ring. Or maybe reuse the O-ring from the OEM CCT? Sorry, have not done this yet but heard a couple comments on slight leak from APEs. It's the O-ring over-tightenning the mount screws won't help at all, just strip the aluminum engine case threads.
battleaxe
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Grn14
Location: Montana
Joined: 02/25/09
Posts: 15511
RE: hot restart noise
05/09/12 10:04 AM
I think 'ideally'...Kawasaki would have made the flow hole for the oil a one way deal...apparently,they didn't.The new tensioner doesn't make any sounds...they fixed whatever it was causing it.I haven't looked at the schematic or close up design of the new one..but Kawasaki made mention of it in all their promo stuff.Nice to have a functional factory part that actually does what it's supposed to do straight out the gate.APE's made a lot of money with the earlier bike's deals.
You know...just the IDEA of having to pull the valve cover off to install something as 'simple' as a tensioner...to me....that's just WRONG.That's A LOT of work doing that.And getting it back together without that gasket leaking.Sheesh.That Valve cover gasket deal...even a qualified Certified Kawasaki mechanic is doin a crap shoot with that thing.That's one pesky bitch there.
* Last updated by: Grn14 on 5/9/2012 @ 10:08 AM *
lytnin
Location: St. Louis MO
Joined: 02/08/09
Posts: 981
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