Hi Guys,

I have a new (old) K100RS 84 model, just changed the crank case breather hose (Big thumbs up to who ever did it last, they left the hose clamp bolts all facing out making it easy.)

The bike is idling very unsteady. it starts OK see video here, but it takes constant attention to keep it going when you stop.

Also the engine is making a terrible rattle at low temperature and revs. Intermittent, but usually there. See this video

OK, so I thought perhaps it was the sprag clutch. Ha I even put a diesel oil in it today, then found out it (being an 84 model) doesn't have a sprag.  I think it's direct? but I'm not sure, does it disengage after fire up?
Anyway if you play the second clip again, I think you will hear the starter wheeze as if winding down as I hit the kill switch, which says to me that the starter has been engaged during the running of the engine.  

Please disagree if you reckon I'm wrong, I hope I am. But thought that this may be the source of the rattle.

What leaves me in doubt is whilst idling and then revving, the rattle is momentarily exagerated as the engine "gasps" to pick up.

When I work out how to do it,

I'll post some pics.

Jez.

Jez you had best redo the links it don't work well.
If you haven't put a new fuel filter in then do so, it can make it starve for fuel if blocked.
Most of the Ks will be noisy at idle when cold and very much so if the throttle bodies are not ballanced and dirty injectors can be the same.
It is possible that the six rivits are loose and as for the sprag they all have one the original 84 had one that was different and are more prone to trouble if they get crud build up in them.
The starter could be engaging if the engine is turning backwards as it comes up on a compression as it stops, this makes the sprag engage and turns the starter a bit. The K75s are more likely to do it than the K100s.
If the starter was spinning all the time with a siezed sprag then it would self destruct very quickly with great fanfare, they don't like spinning that fast.

"great fanfare" funny, not what you want to be sitting over.

Check the 3 rubber blanking plugs that are on the front 3 injector bodies. Where a set of vacuum gauges would connect to.
Are they there and are they disintegrating?
Make sure the hose on the rear injector is a good fit too.
Don't forget to check the O rings on the brass adjustment screws on the TB's. They can crack after 30 years. Remember to count the number of turns when removing them unless you're going to sync them anyway.
Sounds like you still have an air leak somewhere.

just wonder if "that noise " is the monkey nuts in the altenator drive assembly

Sorry guys, I got distracted building a shed, fitting another one out, making a laundry bench etc etc, oh and waiting for my 2nd hand Final drive from America.

No, not the monkey nuts. Oh they were shot alright, but whilst waiting for the new FD I started exploring the rear end of the K. Removed wheel, alternator and the monkey nuts, started it up. Still clattering. Got down to the spline of the Intermediate shaft ? the shaft that drives the alternator. The bearing seems wiggly. So I intend to change the bearing here, and replace the output shaft rear seal while I'm this far in.

I have a foggy recollection of Rick G recommending it,

 I feel like I've been distracted for too long, time to get back on the bike..... well fix it first.

 
Jez

welcome back jez .....
go for a ride first mate

alby has done similar ...plus the output bearing as well ...still has the rattle
looking into it much deeper myself pretty soon

Hi folks,

It's been a while since I've been here. but for the sake of reference and my own frustration at following threads that folks walk away from after the problem is solved I 'll write the end of the story (well chapter)

I replaced the Thrust washer that goes between the clutch input and the Main drive engine output and to my amazement this little old fibrous  washer seems to have taken the rock out of the blender.

Much happier now, just gotta get to the fuel prob now, see you in another thread!

 

Jez

great news !.
thanks for sharing the joy

Jez wrote:Hi folks,

It's been a while since I've been here. but for the sake of reference and my own frustration at following threads that folks walk away from after the problem is solved I 'll write the end of the story (well chapter)

I replaced the Thrust washer that goes between the clutch input and the Main drive engine output and to my amazement this little old fibrous  washer seems to have taken the rock out of the blender.

Much happier now, just gotta get to the fuel prob now, see you in another thread!

 

Jez

Is it #10 in the diagram? Thanks

My bike makes similar rattling noise, but not when idling, it appears when accelerating (high torque transfer) only

billy_k100 wrote:
Is it #10 in the diagram? Thanks

My bike makes similar rattling noise, but not when idling, it appears when accelerating (high torque transfer) only

Yeah Billy that's the one I know the part number is one another thread somewhere here, I got mine on Ebay out of NYC.
Oh yeah..........
On the Fische it says 11211460873,(I just googled part number and the Ebay sale turned up) Also have a look at the post by The Postman, he seemed to have the same prob.

Good luck,

Jez.

Jez wrote:

billy_k100 wrote:
Is it #10 in the diagram? Thanks

My bike makes similar rattling noise, but not when idling, it appears when accelerating (high torque transfer) only

Yeah Billy that's the one I know the part number is one another thread somewhere here, I got mine on Ebay out of NYC.
Oh yeah..........
On the Fische it says 11211460873,(I just googled part number and the Ebay sale turned up) Also have a look at the post by The Postman, he seemed to have the same prob.

Good luck,

Jez.

great! thanks!