Got a bit of a clatter...

[Humey13]

G'day all!

Going to ask a question that's probably been asked before, and to start with, yes I've searched the site and done the research on CCT's.

2010, S10, 21,000kms.

Today's ride was 50/50 on road and on loose gravel tracks. On the gravel, I switched the TCS to either 2 or off. Pulling out of long corners in the gravel (expecting the rear to let go) it would sound normal, then for a split second it would get a rattle/clatter through the bike then as the revs increased it would stop.
It almost feels and sounds like pinging or detonation or even a dodgy gearbox, but I couldn't get it to happen on the sealed road, no matter how much load I put on it in any gear at any rpm. 3500rpm or so, reasonable throttle, loose surface.

Free-rev is quiet, start-up start-up is quiet, load with full traction is quiet

Was wondering if it's got something to do with engine load then as the rear wheel breaks free it pings until the fuelling adjusts?

Anyone else got a monkey with a hammer in their engine?

 

[LostDonkey]

G'day mate.
So it happens with TC off as well? (You mention it happening with TC2 selected which when the TC kicks in, it sounds about right).

 

[Humey13]

Hey Donkey

Yeah it's a strange one, if it happened to my YZ450 I'd swear it had done a bottom-end, but this seems to only be on loose surface when I'm asking the rear to step out. Certain load and revs, TCS off, pulls smooth then horrid rattle then goes away. There are a lot of things that need to line up before it'll do it.

 

[LostDonkey]

yeah, that's odd. similar to you I ride with TC off all the time off-road and enjoy hooning the rear at any opportunity and mine stays smooth throughout.. I'm sorry to say, I would only be guessing if trying to suggest anything.

 

[Humey13]

Cheers mate, no drama. I'm guessing too at this stage.

I'm actually a mechanic which naturally makes me listen to EVERYTHING and I may even be being paranoid, it could be normal for these but once I heard it... I couldn't unhear it. The best way to describe it, is... you know that rattle Ducati dry clutches have? It's like that for a split second.

I'd like to ride another one to see if it's just what they do, but I'm half expecting someone to chime in with a "Yeah mine does that, it's because ...blah..".
I've only had it for a month so I'll do a full service on it and see if I can shut it up.

 

[Jlq1969]

Start with the cheapest, cross-shaft?

 

[Humey13]

Is there a reason they have issues with those? 20 thousand kms?

 

[Jlq1969]

Is there a reason they have issues with those? 20 thousand kms?

20000km, no ..... 2010, maybe it's dry ... any way, is easy and cheap to discard it as a problem

If it is not right, it will always hit when there are differences in rotation between the engine and the wheel

 

[cyclemike4]

OK this may not help you and it may not even be what you are describing but I never run traction control on. I cross a gravel stretch every day going in and out to work. Of course some days when I am feeling good I have to ride it sideways. I have found under hard throttle with the bike really driving no noise. If I am just a bit pitched out under light throttle and hit some rocks or chatter bumps the rear suspension and drive line will chatter. I can tell it is the drive line though. the motor still sounds great at that rpm. As a matter of fact the 3500 is about what mine is turning at that point. I have a 2012 so it is the same bike mostly.

 

[Humey13]

This is going to sounds ridiculous, but what are you referring to by "cross shaft"?
As in gearbox or final drive?

 

[jbrown]

I assumed cross-shaft was referring to a u-joint.

 

[Humey13]

I assumed cross-shaft was referring to a u-joint.

Sometimes you'll get the same name for completely different parts, even in the manual. Just wanted to know if it meant engine or driveline

 

[Humey13]

OK this may not help you and it may not even be what you are describing but I never run traction control on. I cross a gravel stretch every day going in and out to work. Of course some days when I am feeling good I have to ride it sideways. I have found under hard throttle with the bike really driving no noise. If I am just a bit pitched out under light throttle and hit some rocks or chatter bumps the rear suspension and drive line will chatter. I can tell it is the drive line though. the motor still sounds great at that rpm. As a matter of fact the 3500 is about what mine is turning at that point. I have a 2012 so it is the same bike mostly.

of course you have to ride it sideways. I haven't had it long so I'm just realising that they get pretty loose without too much trouble. All that aside, you're right on the money with the conditions and symptoms.

 

[Boris]

Humey13, motorcycle noises are difficult to describe/understand unless you ride the bike, so please bear with me and sorry if I’m going in the wrong direction.

I have a Gen 1 bike like yourself and often experienced a noise and clatter through the bike, always fairly low revs in a highish gear. For example 4th gear at 2500 RPM, then accelerating through until 5-6000 RPM. For a very short time through these revs the clatter/chudder would occur, not always, but often.

On mine, it was the clutch basket. Upgrading to a Gen2 basket resolved it.

Note - my experience is all on tarmac.

 

[Don in Lodi]

If it wasn't TC I was going to guess drive line lash as well. I like the clutch basket thought as well. Those torque springs can be pretty sloppy and can rattle with rapid torque on/off loads.

 

[Jlq1969]

This is going to sounds ridiculous, but what are you referring to by "cross shaft"?
As in gearbox or final drive?

u joint is better named

 

[ballisticexchris]

Check your skid plate that it’s tight

 

[Tenman]

FWIW If you put some dynamat in your skid plate. It ill kill alot of engine noises.

 

[Humey13]

Thanks for the replies and advice legends

I'll take it all on board and check all those things.
A bit of an update on that...

There's torrential rain in Tasmania at the moment so I figured there's no better excuse to open a beer and give it a big birthday. All fluids changed, check all the bolts on everything etc etc.

Found when draining the final drive oil it was BLACK. Moosh all over the magnet in the plug.

When draining the engine oil, noticed one of the drain plugs had no washer/gasket. Engine oil was normal colour but waaay too much of it.

The (aftermarket alloy) skid plate bolts were tight but it was a little loose on the rubber mounts.

At the end of the day, I threw that question out there because I've only had this thing a short while and wanted to know what was normal. I've just learned that whoever owned this thing before me had no interest in maintenance or reliability. Hopefully it'll be a typical Yama and plug away regardless.

Cheers again gents. I'll have more questions later.