27k miles, loose timing chain

[Adroit]

I try to do most of my own maintenance, but I was a little worried about the valve adjustment at 26.6k miles, so I took it into the dealer where I bought it and they let me watch them work on it. While he was working on the bike he found that the timing chain was really loose (it came off the intake sprocket when it wasn't supposed to), so he recommended having the timing chain replaced.

From what I've read, it seems like the timing chain shouldn't be so loose with less than 30k miles on it. The mechanic asked if I used the engine to slow me down a lot (which I do all the time), and he sounded pretty confident that this was the cause of the problem. I guess I'm just posting this to ask if anyone has any other ideas as to why it could be so loose, or a little warning that engine braking may cause extra wear on the timing belt.

 

[SixRFixR]

Sounds like an upsale to me. I would suspect a problem with the tensioner before a stretched chain. I don't see a spec for a pin-to-pin distance on a healthy cam chain. There is a spec for tooth wear on the cam sprocket teeth (1/4 of the side). If they can't offer a measurement, they're blowing smoke. The sprocket and chain should be changed as a set. If they don't offer that, they're blowing smoke. I'd tell them to make sure the tensioner is working and skip the cam chain replacement.

 

[zcypher]

yep, i would also suspect tensioner first... i know that was the cause when the timing belt gave out on my car. i always use the engine to slow me down when driving or riding too... and most of the vehicles driven in my family have been driven similarly without any strange failures.

 

[Marthy]

Im on few FZ forum and the hydraulic tensioner seems to be a general issue I n Yamahas. Rules of thumb, change your tensioner every time you check your valve adjustment.

Sent from my SAMSUNG-SGH-I337 using Tapatalk

 

[FastFreddy]

A loose timing chain would be a good reason to open the rocker cover, otherwise to be avoided on Japanese engines, keep them sealed and stop imagining that your valves need adjustment.

 

[FastFreddy]

or

Has anyone ever adjusted the valve clearances and found modern engines to be out of whack ?

I figured they harden the valve seats and use material that doesn't wear as easily as old engines.

 

[SurfJunkie]

Yes, valves stretch over time requiring adjustment.
Yes, the seats these days are made out of harder material than the valve, which means the valve stretches instead of the valve seats wearing.
It has everything to do with the multiple heating and cooling cycles seen during normal operation, but if you think you know the engine better than the engineers who designed it, by all means do whatever you want. While you're at it, never change your oil filter and throw some olive oil in the crankcase. I've heard it really helps things along.:thumbdown: Never ever check your throttle body sync, or adjust your clutch lever, or lube your cables either.


If you fire the bike up cold, you can hear the valves until the oil is at temp.
Get the bike up to operating temp and leave it idle. If you hear ticking (like when its cold) , you should probably check your valve clearance.

Back on topic, OP I vote tensioner as well. Stay away from stealerships! You have a retarded grease monkey claiming that downshifting / engine breaking killed your timing chain. Do the work yourself or find a local speedshop with a good reputation that other local riders trust.

 

[yellowfz]

Here is a cool cutaway of a R6 http://images.motorcycle-usa.com/PhotoGallerys/YZFR6_Exhaust06A.jpg can see how tensioner works.
Think I would go with the manual adjuster if I changed it out myself.
Seems Marthy's famed 2014 FZ09 is prone to do this too.