Author Topic: Not wanted noice on A10  (Read 1844 times)


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Not wanted noice on A10
« on: 06.01. 2007 19:41 »
Advice needed: The noice coming from register side, intermediate pinion, clic-clac noice
So far sorted out:  this clic-clac comes when exhaust valves starts to close, as far as I
understand this is when valvesprings/via lifters starts to "push" the camshaft for a short while.
Clic-clac occures only on exhaust side, both valves, not when intake valves are closing.

Engine has not been running for awhile, this came up by tuning the engie by hand.

-the timing gears are weared out?
-intermediate buches are weared out, outer feels ok, inner not..?
-intermediate shaft is not straight?
Camshaftbushes feels thight

Engine has to bee sorted out before put into use,  on my spare-engine there is no clic-clac

Any advice on this forum? Has anyone similar experience?




Offline fido

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Re: Not wanted noice on A10
« Reply #1 on: 06.01. 2007 20:34 »
I had something similar with the A7SS. In my case the pushrods had flared out where the hardened end pieces meet the tubular part. This meant they were now too short and the underside of the rocker arm was hitting the edge of the valve spring collar.

Offline dpaddock

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Re: Not wanted noice on A10
« Reply #2 on: 09.01. 2007 15:36 »
Good info, Fido.

No offense, JN, but please have your postings proof read so that we can better understand your needs.
'57 Spitfire

Offline a10gf

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Re: Not wanted noice on A10
« Reply #3 on: 10.01. 2007 21:20 »
Hi Johan, and hello to Finland, that's where you are, no? Welcome to the A forum, hope you will find help & info. Don't worry about the english details, if there is something not clear, we'll ask. If you have a picture, post it in bikes & pictures.

And by the way, I have some click-clack timing side, never really sorted out, and difficult to locate, wondered, among other things, if was too much side play in the camshaft, something with the breather etc. Not critical in my case, but always nice to get rid of mechanical noise.


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  • Guest
Re: Not wanted noice on A10
« Reply #4 on: 16.01. 2007 19:32 »
Thanks for help so far, meanwhile something has been sorted out:
The inner bushing of the intermediate pinion seams to be weared.
It is not easy to locate, when the outer bushing is quite tight.
Anyway, this engine will go into pieces, again, when crankcases are
apart, the inner bush can be checked.
The two intermedite pinion bushes will be changed, and I hope for the best.
For best result, they should be reamed in line, for best fitting, not just hammered into
the cases...   

Hopefully nothing else has to be changed. The whole pinion chain might be
to their end. This can be sorted after bushing change.

Thinking of this noice, over the years, it has followed this engine for some time already..
Always thought clic-clac coming from valves ore tappets
Erling: Camshaft&breather in my case ok, but will be checked again.
Digitalpicture not availble, but one picture of my bike is in Classic Bike Guide-magazine N8/2006 p. 88       

Further repport on this forum to come.




  • Guest
Re: Not wanted noice on A10
« Reply #5 on: 04.07. 2009 06:37 »
Hello to Finland. I have come up with this same problem on my '54 A7. Intermediate or idler gear goes click-clack as spring pressure (I think) turns the cam gear forward. Usually the cam is giving some small resistance to the idler gear, but at two points 180 degrees away from each other on the cam gear, the cam gear gets a forward shove from the springs. So the lash between the gears shifts and there is a click, then a clack as it shifts back. Am I right? Did you ever get yours sorted? Anyone else out there--does this deserve a new set of gears, valve train work, or just grin and bear in until the exhaust note covers it up?

Online BSA_54A10

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Re: Not wanted noice on A10
« Reply #6 on: 04.07. 2009 10:29 »
A badly worn cam follower will also make this sort of sound
Bike Beesa


  • Guest
Re: Not wanted noice on A10
« Reply #7 on: 04.07. 2009 19:28 »
OK, thanks, Trevor. I've noticed that when the timing gears are turned by the cam pinion nut instead of by the crank, the noise is absent. I'm thinking this is because there is then no alternation in the lash between one side of the gear tooth and the other as is the case I described in a prior post. Can you think of a reason the cam follower noise would also disappear when the gears are being turned by the cam nut? Thanks,



  • Guest
Re: Not wanted noice on A10
« Reply #8 on: 17.07. 2009 20:11 »
Little update here on the gear noise. There was excessive lash between the cam and idler pinions. As it turns out, a prior wrench had an A65 numbered cam gear mounted. Replaced with new A10/A7 cam gear et voila, no more click/clack. Not that the engine is now totally silent, mind you, but certainly a step in the right direction. Cam followers this winter.