The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: broom34 on 03.05. 2010 11:13

Title: Clicking noise
Post by: broom34 on 03.05. 2010 11:13
   Anyone out there that can help me please ,I've just rebuild my A10 Plunger and she runs very well  "but" there's a clicking noise coming from the engine when she's stationary ,At first I thought this may be the tappets but after adjusting them 3 times I've ruled them out, I have a sneaky suspicion that it's the push rods they maybe two long or two short I just don't know can anyone throw any light on this problem as I'm in the dark!.

Title: Re: Clicking noise
Post by: RichardL on 03.05. 2010 12:15

One thought I had was that it might be a loose generator chain flopping about against the inner timing cover.

It would be a good idea to isolate the general location of the noise. Are you familiar with the technique of probing for noise with a long rod touching the engine at one end while contacting your ear at the other? At the ear end, the rod should close the ear by pressing against the tragus (see the picture).

Richard L.
Title: Re: Clicking noise
Post by: MikeN on 03.05. 2010 20:44
Does it click if you remove the rocker inspection covers? any witness marks inside the covers ? Ive got an old cover in my box of bits with some great big gouges in them from the rockers. With covers removed, if it still clicks (carefully) put a finger on the end of each rocker in turn and turn the engine over,you may feel it clicking on one or more .That might give you a clue as to where to look next.
Title: Re: Clicking noise
Post by: muskrat on 03.05. 2010 20:55
G'day Richard,
                   I assume you mean when you turn the motor over by hand. you will get a click click sound every 2nd revolution. This is the backlash in the cam gear. Only heard when winding over by hand as at one point the pressure from the valve springs force the cam backwards. No need to worry.
PS Mike & Richard's answers also have merit.
Title: Re: Clicking noise
Post by: Brian on 04.05. 2010 07:50
This seems to be a bit of a thing with A7's and 10's. Muskrat is right with the cause but some seem to make quite a audible noise while others are silent.

I had the same thing with my 51' A7 and spent many, many hours trying to work out exactly what it was. I am not sure if some have more clearance in the meshing of the gears or maybe there is some very slight variation with the teeth profile but for some reason some, like my A7, make quite a audible click. Mine has been doing it for about ten thousand miles now with out any problem.

Certainly double check everything to make sure it is not the generater chain or anything touching anywhere but if you cant find any problem then I would let it be. If you take the timing side off and kick the motor over you will be able to hear the noise, then remove the idler gear and it will stop.

Richard L's advice for listening is good, I use a screwdriver. Stick the handle in your lug ole and put the tip on the area of the engine you want to listen to.
Title: Re: Clicking noise
Post by: MG on 04.05. 2010 08:11

There is a very interesting video on youtube about the Triumph factory. It consists of 3 parts, here's the link to the first one: (
The remaining two parts can be found from there.

Check out the section about the engine gear wheels (pt1, approx. 5:58). You can see the guy trying different pinions until he finds a well-matching set.
Although this is Triumph, I guess this had been common for our BSAs, too. No one knows what bits and pieces had been fitted over the years, so I could imagine that there are good and not so good matches around, some making more noise than others.

Btw, the rest of the video is very interesting, too.

Cheers, Markus
Title: Re: Clicking noise
Post by: broom34 on 06.05. 2010 09:56
Hello All
               Thank you for all the replies and very interesting they were too ,they will keep me busy for some time ,and lets hope that one of your suggestion solves my problem ,once again thank you all.