2500rpm clatter

[golden chicken]

Hey guys. I posted over on SVR a couple of days ago, but haven't received any input yet. Perhaps one of the gurus here can help.

2005 SV650 with 32,500ish miles.

I've noticed an intermittent clatter coming from the motor at 2500rpm. It seems to happen more when the bike is hot, but not every time. I do have it isolated to the motor, as opposed to the drivetrain, by pulling the clutch lever and revving to 2500 while stopped (I can cause clatter that way sometimes), and by pulling the clutch and letting the rpms change while coasting (clatter stops). It does not clatter at idle, nor does it clatter over 3000 rpm (or maybe I can't hear it any more).

I notice it most when coasting/decelerating through 2500 rpm slowly, it's not like I lug it around at 2500 rpm all the time.

My oil level is acceptable, with just 2600 miles since the last change. I am planning to change in 400 more miles, as usual.

I suspect a lazy timing chain tensioner. Just looking for confirmation/consensus from the community.

I took a peek in my service manual, but I can't tell if the tensioners are oil pressurized or if they're only on spring tension. Thanks in advance.

[jasnmar]

I know shit about SV's.

In general, for a clatter that happens more at temperature, I'd first rule out valve adjustment issues.
Again, in general, clatter isn't nearly as troublesome as the alternative if it is from the valves, but it probably indicates that they are due for a check.

I assume the SV's come stock with an automatic tensioner. I know on many of the Honda's "they" recommend replacing the automatic one with a manual one. No idea on the SV.

Valve clearances are at least easier to check than replacing the cam chain

[dontpanic]

The can chain tensioner on my SV1K was spring-loaded only. No provision for oil pressure.

Consider looking into synching the throttle bodies. Also could be worn clutch plates rattling. Your comment about the clutch behavior could affirm that, which is probably aggravated by the TBs if not synched.

[golden chicken]

Oh, sorry if I was unclear. It clatters in gear, clutch engaged (lever out) at 2500 rpm.

I noticed it first when slowing to a stop when I left it in gear and let the engine speed fall to 2500 with the clutch engaged. At this point, pulling the clutch lever and letting the engine speed fall to idle while still rolling causes the clatter to stop and bringing the revs back up to 2500 without engaging the clutch will bring back the clatter.

That's why I don't think it's drivetrain.

[Pigman]

CCT..........

[Chippertheripper]

I have to ride mine again to remember, I just don't think the motor likes stumbling along in gear at that low an rpm.

[SVenpointsixtwo]

My SV1000 had similar behavior, and I'm pretty convinced it was the infamous "chutter", although I never pulled the clutch to find out. Not sure if the 650s do something similar.

http://www.svrider.com/forum/showthread.php?t=115989

[Tricky Mike]

Sure it's not the drive chain slapping around when you pull the clutch in and it goes from either positive throttle or engine braking to freewheeling? Is it too looseygoosey?

[golden chicken]

I don't think so. It clatters both when slowing and when lightly gassing it. It also clatters when the bike is at a standstill and I rev it to 2500rpm. I don't remember if I was in N or if I had the clutch lever pulled when I did that.

Of course, sometimes it behaves totally normally, as it did for 450 miles on Sunday at the Seacoast ride.

[Tricky Mike]

It also clatters when the bike is at a standstill and I rev it to 2500rpm.

Ah, as you were then...

I'd take a long screwdriver (unless you have a mechanic's stethoscope) and press it to my ear and the cam chain tensioner (and/or other areas looking to pinpoint the sound).

[golden chicken]

Yeah. That clutch basket thread has me concerned. Maybe I'll inspect the tensioners first, possibly replace them, and go from there.

[DaveZX6r]

You still haven't mentioned when your last valve check or tb sync was.

[scubasteveRR]

it must be the flux capacitor, you should be able to get another one from the Libyans

[golden chicken]

Last valve check was at 18000 miles. Never synced the TBs afaik.

Tonight's ride had a little bit of clatter, but no vibrations that were described in that clutch basket thread, so I'm definitely leaning towards tensioners now. Next chance I get, I'll be listening in with a screwdriver.

[stoinkythepig]

Sounds like a classic tensioner issue. Valves get quieter with miles as they tighten up and do not change noise level much with RPM, so rule them out immediately. The cam chain is like a big guitar string, sections of it between sprockets want to resonate at certain RPMs. That's why all the chain guides are curved, the curves prevent any straight/unsupported runs and the tensioner keeps the chain tight to the guides. If the tensioner is not working properly, sometimes the chain will leave contact with the chain guide when it the RPM is matched up to the resonant frequency of that section of chain. The temperature and viscosity of the oil can help damp the resonance, so the noise may come and go with changes in temperature too.

[golden chicken]

Update:

Valve clearance has been checked and found to be within spec and timing chain tensioners have been replaced. The clatter persists. I will be doing an oil change soon. I hope nothing falls out.

[stoinkythepig]

That's a bummer. I'm baffled. You are certain it's internal to the motor, right?

[golden chicken]

I'm fairly confident it's in the motor/trans, yes, because it does it in any gear at 2500 rpm and I was able to make it clatter at 2500 rpm while stopped with the clutch lever pulled in. I didn't have time to try clicking it into Neutral because the light changed, but that will be the next thing.