New to me K100. Replaced water pump seals and did the camchain and guides yesterday. There is still this annoying screech, high intensity rattle like an alternator bearing. Took the alternator out today and it’s fine. Does anyone have any ideas please?

If the noise is evident while the bike is stationary try using a automotive stethoscope to track down the source of the noise. Stethoscopes can be had pretty cheap and are handy when chasing noises. If you don't want to go to the expense you can use a long handled screwdriver, put the blade on the source and the handle to your ear.
Regards Martin.

Try pulling the clutch lever to see if it stops.

thanks all, investigation ongoing. It could be an exhaust resonance.

nobbylon wrote:New to me K100. Replaced water pump seals and did the camchain and guides yesterday. There is still this annoying screech, high intensity rattle like an alternator bearing. Took the alternator out today and it’s fine. Does anyone have any ideas please?

did you inspect the rubber bushes that interface with the alternator drive cup (known by many bmw folks as Monkey nuts  as they are connected together rather tenuously and not very big )

we have seen a few issues about noise seeming to come from that area usually the rubbers is the issue  

but could also be the drive shaft that runs the alternator out of the motor ...is that bolt that holds the drive impeller up tight ?

good luck

yep, monkey nuts all ok and everything tightened down. The outermost alternator bolt was missing so have replaced that.

I feel positive it’s coming from the front and low so for the 3rd time i’m takin he pump off to see if I can see an g tat would cause it.

You say still a screech. Was it there before doing the cam chain and pump? Did you run the engine without the alternator? That would rule it in or out?

Odd that it happens in a 3-4000rpm rev range.

How exactly was the cam chain tensioner etc fitted? 2v or 4v engine?

Ok so I removed the pump and found this! the screeching is obviously lateral play at certain rpm.
Any ideas as to why? I also removed the sump and found a lot of crud in there so I’ve cleaned that up.
The new pump gear was drawn through the seal correctly so I dont know why it should have done this. Is the block now toasted for running without screeching?

nobbylon wrote:Ok so I removed the pump and found this!
The new pump gear was drawn through the seal correctly so I dont know why it should have done this.

The crud is likely to be excess assembly silicone which generally is not an unusual find in a sump that never been removed and cleaned.

It is recommended in this document that installation of new style pump seals include a new spacer bushing and a stamped impeller to replace a cast impeller. Did you include those new parts in your installation?

Yes I replaced all new seals, spacer and impeller.

I’ll start it up again today and see what it sounds like.
Options?
1/ shim between back of both gears. Would this reduce oil pressure?
2/ fit a later pump with the larger gear to span the wear area?

I can only think that there has been movement of the shaft downward at some point and that has caused the wear. The photo’s make it look a lot worse than it actually is! 
The only thing keeping the larger gear away from the block surface is spring pressure from the seal. Would it help to pull the gear a little further through the seal thereby increasing the tension of the gear toward the front of the bike and therefore away from the block?
When the pump is assembled I can push the impeller against the spring until the impeller hits the pump body and the gear does move very slightly proud of the pump body. Is this normal? thanks all.

The gear should sit flush with no movement and don't shim the gears as that will cause a no oil pressure situation.

The gear does sit flush BUT when I push the impeller it can move against the spring in the water seal. It only moves back until the impeller hits the body. This is with the pump off of the bike. When mounted there is no movement.

Just refilled with coolant and oil and started it up. Noise still there and I’m positive now that it’s the interface between the gears and engine block. An added bonus is that after taking extra care in making sure all surfaces were dry before applying a coat of hylomar blue, I now have an oil drip! Pump been off 3 times now and I’m sick of emptying and refilling. All in all not a great K experience so far so I’m going to try and find a later big gear pump and after that will fix the drip. Driving me bananas. Never had any of this b@@@@@@s with my airheads in 20 years.

I did however manage to succesfully remove the alloy covers from my old /6 shocks 

There should not be any movement even when the pump is off the engine. It is not assembled correctly.

ok thanks Rick, I will take it off again and pull the shaft further through the water seal even though it is flush at the moment. Will report back, cheers

I would say that is where the problem is. It needs to be taken as far as it will go with reasonable force. 6mm key in one end of the shaft and open end spanner the other and make it tight.
I think that will solve the problem and once it's done a ride is on the cards, you will need one.

Blue Hylomar may not be as effective as three bond in creating a good seal.

Mike

now you tell me Mike
well I’ve drawn the gear shaft through until no free play, still a screech between 3000 and 4500 pfff. First time I did this I used silicone clear, no leak, next was hylomar blue and a misting of oil, 3rd time was hylomar and a drip and todays effort with hylomar has left a puddle so lesson learned. Ordered some Permatex ultra blue and I’ll put up with the screech if I can get it oil tight!

Rick, 
when I pull the gear shaft through the new seal how far is it supposed to be pulled through? Using washers and spacers I can get rid of end play but still continue to pull or should I say now compress the face of the seal against the spring toward the pump body. Eventually the spring will be completely compressed if I keep adding washers to the stack so that it goes tight surely?
I’ve ordered a new water and oil seal AGAIN and await my Permatex.
Would you use black or blue Ultra? I have both on the way.
thanks for everyone’s patient replies, I’ve been wrenching on cars and bikes for 40 years but this thing was sent from somewhere to test me i’m sure,
j

Have you removed ALL of the old water seal. If not you will have problems.
When assembling enter the shaft through the oil seal into the water seal then using a long bolt and washers pull the shaft through just far enough till you can start using the supplied bolt, impeller and alloy spacer then do the bolt up till tight which will pull the shaft and gear into the correct position. You should have the pump ready to place on to the engine.
The last pull should be done using the new pressed steel impeller and the alloy spacer and the new bolt. Tension should not need to be any more than 14-16ft/lb. That should pull the shaft through the water seal far enough that the gear will sit flush with the pump body so that there is no end play when attached to the engine and about 0.025mm clearance of the gear to the pump body and or engine. The gear should not exert any force against the engine or pump body, it should float freely with an absolute minimum of clearance so as to get maximum oil flow. At the same time the impeller should clear the pump body by 0.5 -1.0mm. there will be that 0.5 - 1.0mm end movement against the spring action of the water seal but when standing there should not be any free movement that is discernible.

thanks for this and yes I completely removed everything and installed exactly and I do mean exactly as you have described. I’m going to take it apart again and redo it with new seals and some Permatex. I will take pictures etc. Installing in the way you described does allow to push on the front impeller when installed and have the shaft move back to take up the gap between impeller fins and pump body. When force is released on the impeller the spring then returns the shaft and therefore the gear, flush with the pump body. The only way to stop this free play against spring is to pull the shaft through further.

Just cleaned and rebuilt the pump again and this time followed the instructions again Rick and have to say it turns a lot smoother than previous attempts. Maybe I had already pulled it through a fraction too far with a washer? who knows but now it turns very smooth so will just have to wait for the sealer and then I can give it another go! Thanks again for the help.

Permatex ultra blue did the job nicely to stop the leaking oil pump and hylomar red on the front cover. The noise is still there so I’m going to assume it’s just worn that way. I can’t hear it when I’m riding and only when I throttle over 3000 ish. Other than that it rides very nicely and will run it around this summer instead of the F650. I’ll pull the gearbox and do the splines sometime in summer. i’m now going to look for an RS fairing for it.
Thanks for all the replies.