Hello again, this is another "is this normal" type question..

With the cold mornings drawing in I've noticed a chatter coming from my clutch, upon relaease of the clutch lever, for the first mile or so of my trip to work.

Seems like it dissappears as the engine heats up.

IS this due to cold and gloopy oil not lubricating? or something more sinister?

thanks

Can rule that one out, it's a dry clutch

Ah.. I see...

Mine does it a bit. Syncing the injection system seems to reduce the clattering.
Thats the air bleed screws, not the butterfly linkages. That opens another can of worms!

Mook, is that a chatter as in stutter when the clutch lever is released and the engagement point is reached? Do you have any freeplay (of say 3-5mm) at the handlebar lever? Or are you referring to a chatter at idle but not while moving?

Two Wheels Better wrote:Mook, is that a chatter as in stutter when the clutch lever is released and the engagement point is reached? Do you have any freeplay (of say 3-5mm) at the handlebar lever? Or are you referring to a chatter at idle but not while moving?

Not a stutter, but a grinding/chattering noise when moving up through the gears just at the point of engagement of each gear.
no loss of power that i can discern, just the noise.

like I say it seems to dissappear after about half a mile or so, and only happens when v cold.

feels like as the bike warms u and/or fluids start to move it dissappears.
might be something to with the shaft?

Hi Mook,
Check the gearbox oil level is it correct? Drain the gearbox and pay particular attention to the magnetic drain plug and the oil coming out, what does the filler plug look like are there any splinters of metal on there or is it all just a grey paste with no gritty bits in it? Did you fill the gearbox last if so what oil did you use?
Regards,
K-BIKE

K-BIKE wrote:Hi Mook,
Check the gearbox oil level is it correct? Drain the gearbox and pay particular attention to the magnetic drain plug and the oil coming out, what does the filler plug look like are there any splinters of metal on there or is it all just a grey paste with no gritty bits in it? Did you fill the gearbox last if so what oil did you use?
Regards,
K-BIKE

Hi,
I haven't checked the gearbox oil but will do asap, I don't have a manual for this so I'm not sure what type/how much goes in.
THE bike was serviced before I bought it in august, so I haven't changed the oil yet.

in fact, I need to find out where to check the oil level.

Mook, go to the Downloads section of this forum. Look for the topic: "download page and password". Login and find the K100/K75 Haynes workshop manual.

In the manual, you will find all the info you require about what fluids and quantities are required for your bike.

Do you have the C spanner (shock preload adjuster) in your toolkit? As you may know, it doubles as the oil level indicator for the gearbox.
Don't worry if you don't, because the workshop manual gives you the dimensions required to make your own dipstick.
I used a plastic chopstick, marked it using the dimensions in the manual and it works a treat...and it saves me getting out the toolkit when I need to check the level.

I hope this helps.

I have the exact same thing happening when I change gears and when I back off the engine when cold only. I've thought about this a lot and come to the conclusion (I believe) that it's caused by a slight amount of wear in the output shaft gear backlash eliminator spring where the spring engages in the locating hole in the gear. This wear effectively reduces the amount of tension on the gear, so the pitch offset is less than when new and when cold and the load comes off the gear I think a slight rattle occurs. At this stage this is my theory because, as you state, it goes away when the engine warms up, so I can't justify dismantling to that degree just to find it. I think a similar noise can be heard if you load up the drive train in top gear below 2500 rpm. Others have written about this noise, I think it would only be gone if a new spring was installed and the engagement hole(s) are not worn.
Anyone with experience in replacement of the spring ?? Comments please.
Regards, Dennis

Dennis wrote:I have the exact same thing happening when I change gears and when I back off the engine when cold only. I've thought about this a lot and come to the conclusion (I believe) that it's caused by a slight amount of wear in the output shaft gear backlash eliminator spring where the spring engages in the locating hole in the gear. This wear effectively reduces the amount of tension on the gear, so the pitch offset is less than when new and when cold and the load comes off the gear I think a slight rattle occurs. At this stage this is my theory because, as you state, it goes away when the engine warms up, so I can't justify dismantling to that degree just to find it. I think a similar noise can be heard if you load up the drive train in top gear below 2500 rpm. Others have written about this noise, I think it would only be gone if a new spring was installed and the engagement hole(s) are not worn.
Anyone with experience in replacement of the spring ?? Comments please.
Regards, Dennis

Interesting, that's exactly what's happening me, noticed this morning that keeping the revs on during gear change (as much as possible) minmises the noise, and it gets worse during engine braking.

Although this sounds more serious than low oil level,
I'm not clear how this would be affected by temperature though.

Mook, I must apologise, it's late here in Tassie (11 pm) and the brain is fading slightly,...... how many K's has your engine done ? Keeping in mind that K bike speedo's are a bit unreliable. My 1988 engine had 140,000 on it and it had loose rivets in the output shaft. It was an ex cop bike and they get a thrashing through the gears, so the 6 rivet assemblies give up. But that engine also did the rattle thing I've spoken of.
Because we tour long distance a bit, and I wanted the peace of mind, I purchased a 1989 engine complete and exchanged. That engine had 101,000 K's on it, no loose rivets, but still does the rattle thing when cold. So, my point here is that I think it is related to the amount of K's on an engine. Others may wish to comment on whether it exists in their engines, and if not, how many K's have they done. I'm pretty sure I'm on the money with this, so when I get time I'll dismantle the 1988 engine to see if I'm correct in my diagnosis.
I'm trying to prevent you from being led on a wild goose chase with this, but at the same time I wouldn't like to see a catastrophic failure, so please continue to forward as much info about the symptoms as possible.
Regards, Dennis

Well I recently turned over 69000(miles),
so what's that? about 110,400 K?

I have the same noise, when engine is cold...

I'm going to disassemble the engine soon to check what it is...

I'd be grateful if you could post any findings on here.
I'd like to get a feel for how easy/difficult this would be to fix.

My bike has a rumble when cold that fits most of the descriptions above. I've never noticed it when changing gears, but certainly if I don't use the fast idle (choke) lever when starting it from cold (results in an idle of about 600rpm instead of 1000rpm), or close the throttle sharply at low speed (eg: pulling up at a stop sign) or load the engine up at 2500rpm or below, it rumbles. All this only happens when cold - first 5 minutes or so. Mine is an ex-Police 1986 K100RT with 124,000km - just clicked over on the way to work this morning.

I believe it is a combination of the output shaft rivets and spring / engagement hole as outlined above. In the short time I've had the bike I've learnt to ride around it (start with fast idle on, use more brake / less engine to pull up at the first couple of intersections, etc) I have no plans to do anything about it in the short term. I've only just had the back of the bike stripped all the way to the clutch to do a gearbox change and it is a bit further still to do the output shaft. I have loose plans to pull the output shaft next time the bike is due for a spline lube.

mook wrote:I'd be grateful if you could post any findings on here.
I'd like to get a feel for how easy/difficult this would be to fix.

Please, here you have the offender:
http://k100rt.aforumfree.com/t1959-1987-rs-engine-small-renovation#13195