tapping sound

[Valker]

I have a tapping sound from the right side of the engine when the bike is hot. Set and rechecked the tappets balanced the carbs and the bike had a new timing chain fitted.

Wondering if it could be the end float on the rocker shaft, any one have this problem before and know the answer please

 

[cookie]

both of my airheads have done this. never worked out what it is.

sounds like piston slap/small end, but doesn't just do it on the overrun as one might expect if that were the case.

it's not end float, mine is virtually zero. if it's anything to do with rockers/valves, i'd suspect the cam followers.

 

[Rob Farmer]

Sounds like rocker end float to me

 

[(RIP) maverick]

Check if the header pipes are sealing properly. My bike made a mighty racket recently when I did not refit the one part of the sealing bush on the header pipe. It sounds exactly like valves or timing chain noise.

Now all gone since I fitted the part back.

 

[BigyellowGS]

I second what Maverick said above.. I had a similar racket from the bitza on/off just after I first had the exhaust made up.. turned out to be it was working loose on the r/h side.. quick tap with a mallet and it went quiet. Once identified I then refitted the pipe/retightened the finned nut and hey presto.

 

[Redboots]

I have a tapping sound from the right side of the engine when the bike is hot. Set and rechecked the tappets balanced the carbs and the bike had a new timing chain fitted.

Ditto. Quiet as a mouse when cold and taps when hot. Makes no difference if its on load, overrun or idle. Drives me nuts.
Cam followers was my next thing to look at in the winter...

John

 

[cristhemuso]

I have shimmed up the rocker shafts in the past but the shims available are not thin enough to remove all the play. You will notice the rocker acts diagonal to the shaft and thus any axial play translates to extra gap under load. What I do is slacken the head bolts which gives the pillow blocks a smidge of movement. I then clamp up the pillow blocks tight together to remove all axial play on the rocker shaft and then re-torque up the cylinder head bolts. You only need to do this once. Note the torque setting for head bolts is low so use a torque wrench to prevent stripping the threads in the casing. I use a valve spring compressor to clamp up the assembly.

 

[cookie]

I have shimmed up the rocker shafts in the past but the shims available are not thin enough to remove all the play. You will notice the rocker acts diagonal to the shaft and thus any axial play translates to extra gap under load. What I do is slacken the head bolts which gives the pillow blocks a smidge of movement. I then clamp up the pillow blocks tight together to remove all axial play on the rocker shaft and then re-torque up the cylinder head bolts. You only need to do this once. Note the torque setting for head bolts is low so use a torque wrench to prevent stripping the threads in the casing. I use a valve spring compressor to clamp up the assembly.

i have done this in the past & it works for a while, but after a few miles, the blocks get beaten outwards by the rocker & i'm back where i started.

also seen several very quiet airheads with end float right at the outer bmw limits.

in the case of my current airhead, i have motoren-isreal fixed rocker supports fitted, with tiny end float gaps.
sounds like end float, but can't be really

 

[Redboots]

I have motoren-isreal fixed rocker supports fitted, with tiny end float gaps. sounds like end float, but can't be really

I have billet mounts as well. Using a stethoscope, (screwdriver), there is no noise from the top-end... all seems to emanate from the bowels.

John

 

[fayeslane]

... all seems to emanate from the bowels.

John

Too much fibre perhaps.............

 

[cristhemuso]

Another thought. The rockers have needle roller bearings in them acting on the rocker shaft. If these are worn you can never set the gap correctly & quieten the engine. As I recall they just drop in (and out) so maybe you can simply replace them? I don't know if you can buy them separately from MW or MB or BMW.

 

[Steptoe]

Check the cam followers - they can often pit or crack causing a tapping noise.

 

[pete.keys]

has anyone tried anything like this?

Suppose to cure all the top end noise and assist in getting higher revs.

 

[cookie]

has anyone tried anything like this?

yes, but without the radial thrust bearings, which are an option.

i found those fitted on the bike as bought, but they weren't motoren-israel jobbies, with machined rockers etc. didn't like them as they are near impossible to set to zero clearance, so reverted stock items.

 

[MattW]

I don't like those radial roller thrust bearings in any application - they don't actually roll. If I wanted a supplementary thrust bearing, I'd prefer some sort of oilite bronze.

 

[Redboots]

has anyone tried anything like this?

Mine look like this and cost half the price from a guy that makes them on the gs-forum.eu

John

 

[Redboots]

Too much fibre perhaps.............

I soon as I posted, I knew I should change the wording

John

 

[Redboots]

Check the cam followers - they can often pit or crack causing a tapping noise.

Cheers, that's where I'm headed next

John

 

[Sylvester]

I have tried just about everything to get rid of "Unwanted" mechanical noise. I have replaced the valves and guides, the timing chain, checked the bores and piston tolerances, end float etc..etc. I know everything is ok now so no more paranoia. Just put the key in it and ride. It will tell me when it's bust. They all do that Sir!

 

[pete.keys]

yes, but without the radial thrust bearings, which are an option.

i found those fitted on the bike as bought, but they weren't motoren-israel jobbies, with machined rockers etc. didn't like them as they are near impossible to set to zero clearance, so reverted stock items.

Does that mean that yours are up for grabs? If so let me know