R65 1981 - metallic noise

[NorR65]

I drove my R65 for about 40 minutes on friday.
When I parked I heard a loud metallic sound which I believe came from right side or front of engine housing. I can describe the sound as "clack,clack,clack". It did not sound like a worn chain, but I think it is the timing chain. My R65 has at least 83.000 km at the odometer and I do not know its maintenance history.
Any ideas?
Thanks

[Mike V]

Nor65,

Have you put a timing light on it yet? Bouncing or erratic light at idle?

[Bob_Roller]

If you have access to a mechanics stethoscope, it can narrow down the area of the noise pretty quickly.

[nhmaf]

I'd first at least pull the valve covers and make sure that your rockers and valves are working correctly, and haven't lost any parts, then start looking elsewhere with stethoscope, etc.    

Does the engine still seem to run well with good power, or is itmisfiring, stuttering, etc?

[NorR65]

I think it runs well but it is my first airhead so I am not sure.
I have listened to a few Airheads on Youtube and my R65 does not sound to bad. I will check valves, check timing and by a stethoscope.
I will inform you about my findings.
Thanks for your help.

[Tv]

When you are checking the valves you need to look through the peep hole on the side of the motor to see the timing marks on the flywheel. While you there check the flywheels ring gear is noT loose.  You can use a screwdriver to wiggle the ring gear up and down. It's a simple check.
That was the case with my bike when it was making a loud rattling noise from mid motor.  It still performed OK and wasn't too loud at higher revs but when idling it was CLACK CLACK CLACK.
Good Luck

[NorR65]

I have at last checked timing with a timing lamp.
The "Z" does not bounce around and is quite easy to see at idle.
The valves was correct adjusted and no loose parts.
I used a stroboscope but it did not give me a clear answer where the problem is. I are not sure it is only from the front but also from the end of engine.
I can move ring gear  with a screwdriver. But I am not sure if I moved the complete flywheel or just the ring gear.
I only hear the noise when idle drops below 900 rpm.

[nhmaf]

I think/hope that you mean "S", not "Z" at idle - the "Z" (1981-later) or "F" (pre-1980) marks should be observed when at full advance ~3500 RPM.  

If the bike isn't warmed up yet and is idling slow because the enricher/choke isn't on, well, they do tend to make some unhappy sounds then.  But if warmed up fully and your idle is still at only 900 RPM you probably should consider raising the idle speed to 1000-1100 RPM, they are happier and smoother there.

[NorR65]

I used the timing light again today in a darker garage and I saw "S" and not "Z" at idle. I drove another trip yesterday and with warm engine and idle 1100 rpm most if not all noise came from timing chain area. Cold engine and around 900 rpm was not the time to listen for noise. I will order a timing kit from Motobins today.
Thanks for Your help.

[Bob_Roller]

If you don't have an alternator rotor removal tool, I would recommend getting one when you order your timing chain kit .

It's pretty hard to get the rotor off without one .

I don't know if the Motobins kit has the o-ring for the ignition 'bean can', may want to get one of these as well if the kit doesn't have one .

[NorR65]

Motobins sells the rotor removal tool.
I think the timing chain kit includes the o-ring and everything I will need.
http://www.motobins.co.uk/bmw-parts.php?model=R Series 2 valve Twin

[montmil]

NorR65,

We discussed a timing light issue previously. What cooked down to a pretty fair consensus is that the timing light's inductive pickup should be attached to the right-side spark plug lead. Also, the timing light should be powered by an alternative source 12V supply; as in another battery. Doing this will give you the most accurate readings.

Just checked the timing on my 1981 last Saturday...

Monte

[Bob_Roller]

Looks like it is included in the kit .

I had my alternator brushes get worn to the point where the "GEN" light would stay on all the time, at 58,000 miles .

I don't know what other owners experiences are with them, but you're not too far away from that mileage, just a thought .

Seeing as you're going to have it taken apart anyways .

[NorR65]

OK, will check alternator brushes.
And I have to check timing once more. I attached the pickup to left side spark plug lead and used the BMW`s battery.
I am looking forward to replace the timing chain. It is real fun and relaxing to repair my R65. It is so well made from the factory.
I have already read a lot on this forum about how to replace timing chain. And I know where to ask if I have problems.
Thanks again.

[Tv]

Regarding being able to wiggle the ring gear - you'll know if it's obviously loose because the rattle it makes when you jiggle it up and down is easily recognisable.  If you need to apply any force to move it up or down it's not likely to be making the offending noise.
Cheers and good luck with the T-Chain replace