CLICKING NOISE

[Schnellfahrer]

For the last couple of weeks or about 200 miles I hear a fairly loud metallic clicking noise when I close the throttle and slow down to  2000 RPM and below.  This is most noticeable in the 3 highest gears and it is not a pleasant sound.   When I coast to around 1500 RPM, still with closed throttle, the bike starts "bucking".  Although I am not in the habit of lugging the engine it will accelerate seamlessly from the low RPMs to cruising speed and beyond.
Also,idling is not a smooth as it used to be and a single metallic click can occasionally be heard at idle. 
Probably unrelated but about 1000 miles ago I adjusted the valve clearance with new and machined shims.
Any advice on this matter is greatly appreciated.

[natalena]

A short video with sound would be really helpful.
Without that, I'd guess (not a good overall strategy) at checking the TPS, although the click it makes is very slight ... also considering my hearing is crap.
I've also seen brinneled headset bearings make a click when decelerating, but you usually notice the poor steering.
Good Luck

[The Mighty Gryphon]

What are machined shims? 

My K75RT makes a lot of clanky noise between about 1200 and 2000 rpm.  It's caused by slop in the dog that drives the balance shaft.  Been doing it on my bike for almost all of the 40,000 miles I've owned it. 


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[Laitch]

I'm probably as curious as Gryph about the meaning of "machined shims." What type of metal was machined to create them? The moto will buck traveling at 1500 rpm in high gears. How many miles on the moto?

[Schnellfahrer]

I had some original BMW K75 shims in my tool box which were "thicker" than the ones I needed to replace some on the bike. In order to get the correct valve clearance I took them to a machine shop which carefully grounded them to the thickness I needed.   I have not had  time to check the valve clearance again.   However, it occurred to me that the outside  of the machined shims may not have had the hardness  any more of unused ones and may have been wearing off  the outer layer.  I will know as soon as I check the valve clearance tomorrow.  Meanwhile I am not riding the bike which b.t.w. has only 31,000 miles.  Thanks for your interest.

[Laitch]

In order to get the correct valve clearance I took them to a machine shop which carefully grounded them to the thickness I needed.   

There are far cheaper shims available. Go to the Alternate Parts section of the site and click the links.

[stokester]

There are far cheaper shims available. Go to the Alternate Parts section of the site and click the links.

... or just drop by the local Yamaha/Kawasaki dealer for some 29mm shims.  The last pair I needed were traded for no cost at the local dealer.

[Schnellfahrer]

Thank all of you guys for your interest and suggestions.  I have checked the valve clearance on all 6 and they are all well within specs. Btw good advice about the lesser cost shims.
I will now look at the driveshaft splines although I lubricated them only 5,000 miles ago and then they looked in perfect condition..  I don't like to ride my K75 when this clicking continues.

[Laitch]

Also,idling is not a smooth as it used to be and a single metallic click can occasionally be heard at idle.

I will now look at the driveshaft splines although I lubricated them only 5,000 miles ago . . ..

The way the splines engage is unlikely to cause clicking. They usually go from quiet to grinding or screaming when they fail. A faulty u-joint might click but neither a faulty u-joint nor faulty splines would affect idling. A faulty fuel pressure regulator might click. An intermittent faulty electrical connection might snap or pop occasionally.

Try to make a recording then post it to YouTube and give us a link to it. That should be easier than disassembling the drivetrain down to the engine.

[daveson]

Try to pinpoint the location of the sound. Does pulling the clutch in affect the noise, or is it louder with the oil cap removed,  or the fuel cap removed?
More related to road speed or engine speed?

[Laitch]

Try to pinpoint the location of the sound. . . . is it louder with the oil cap removed . . .

If the air intake system is not leaking, the engine is likely to struggle or stall if you do that.

[daveson]

Too right, I keep forgetting about that thing about bricks. 

[Schnellfahrer]

Fortunately the saga  does not continue. A friend of mine alerted me to the fact that one or more of the throttle body synchronizer connectors may not be properly capped. It turned out that both had lost their cap which resulted in poor idling, backfiring and more than likely the clicking sound I brought up initially. After I capped them the engine ran smoothly without the metallic clicking noise and all I had to do was lower the idling RPM which had gone to 1500.
Again, I want to thank al of you for your valuable input.

[The Mighty Gryphon]