[BurgmanFran]

Hi Everyone,

I found this item in the engine oil strainer compartment of my K3 AN400, just under the strainer.
Has anyone got any idea what it is? Where it's from? and Should I be concerned?
[attachment=0:1oq5np1h]engine_part.jpg[/attachment:1oq5np1h]

The bike was running fine until I took it apart

Thanks for reading
Cheers
Fran

 

[BurgmanFran]

I also meant to say that it's about 40mm (1.5") in diameter and is very thin.
On looking at my own post I thought it looked like a regular washer, which it is not.
Regards
Fran

 

[Ralph M]

Looks like a wave washer, balancer shaft maybe?

 

[Ralph M]

Does it sound ok no rattles? if it's what I think it is the balance shaft is driven by a split gear
with springs so the gear teeth are slightly out of phase taking up the backlash so it's quiet
the wave washer keeps the to halves pressed together but allows a little moment, I think.

 

[BurgmanFran]

Thanks Ralph M, following on from your lead I managed to locate the part on a fiche.
(number 7 as shown below).
[attachment=0:241o3vz8]crank_blancer.jpg[/attachment:241o3vz8]


I don't know if there is a rattle or not at the moment as I have the rest of the bike stripped down for some serious anti-corrosion treatment.
I'm wondering if it's ok to still drive around (when I put it back together ) or is there a risk of doing some serious damage.
Or is it an easy enough job to rectify this given that I have the engine/drive unit out at the moment.

What do you think?
Regards
Fran

 

[Ralph M]

Mmmm that looks like the beast, I would do it wile the motors out, you never know what else may
have happened.

 

[Scootereno]

From the damage it looks like part # 7A might be missing or installed on the wrong side of the snap ring.

 

[cliffyk]

Here's a photo of the assembled balancer "scissor" gear:

I have seen failures of similar spring washer loaded anti-backlash assemblies when they were assembled with too little (I.e. no) free-run clearance in the stacked components; the stack binds and something has to give. However in this component the relative motion between the stacked pieces is very small--though things like that happen. It may be a common failure, I have never pulled the strainer on my '03--next time I change the oil I will and see what I can see.

Replacing it is a "split the crankcase", full disassembly of the engine, project...

----------------------------------------------------------------
My grandfather, a stationary steam engineer, always told us "If it was built by men someday it will break."

 

[BurgmanFran]

Thanks Cliff, It's good to see an actual photo of what the piece looks like in situ.
I think I'm going to put the bike back together anyway and see how it runs for a while.
I'm hoping that this piece may have been lodged in the strainer for quite a while without adverse effects.
It's also a job that I don't feel confident about taking on myself right now.
Regards
Fran

 

[cliffyk]

That would be my plan. The spring washer is there to force the scissor gears together as was stated earlier, its absence will allow the inner gear to move about a bit more than intended on the outer gear's hub--which will make some noise and accelerated wear --however I suspect these effects will be minimal as the spring washer is so thin.

We have no idea when it failed, and it's been 30000 miles (kilometers?) now...