Knocking noise also but on a model 8

[Ozmadman]

I have carried this on here from the thread below as mine is a model 8.
http://www.ajs-matchless.com/forum/view ... 20#p111744

Well I spent some time today trying to find the root cause of the erratic knocking noise which I can now hear when the bike is stationery if I get it at the right revs. Having a good listen around with a screwdriver I can't really hear too much in the n/side crankcase area so maybe it isn't the breather stator rattling around as I thought it might be. It seems to be coming from the o/side as when I listen on the crankcase just under the barrel I can hear it there and it is louder when I remove the oil filler cap?? So possibly cam shaft problems? or even the stator noise travelling through the crankcase. It isn't as loud stationery as when moving but it is definitely the same noise like an erratic clacking sound. Also how much oil should one of these engines use presuming it is not leaking out anywhere, I have put in around a 3/4 of a pint in 500 miles..

Many thanks

Paul

[cbranni]

Hi Paul, 3/4 pint is not a lot along side my 350, quite a bit comes out of the breather but keeps the chain well oiled, regarding noise all mine are quiet, tracing a rattle can be hard work even using a listening device, there is a post of mine on here about my B40 which had a "ting" when running, using a listening device it was near side upper cylinder area, when I gave up listening and stripped the engine again it was a loose key on the cam drive gear which is off side and low down, my gut feeling is clatter and rattle is cams, followers and rockers, rumbles and knocks are mains and big ends only my opinion).(
You could check alternator rotor is not loose, not the nut but the actual rotor, there is of course the breather stator I have never heard how a loose one sounds, sorry.
Tell you what put a video up on you tube then we can all listen to it, I've babbled on enough, must go make my tea and do my snap for work.

Colin

[SPRIDDLER]

Paul, I can't offer any suggestion regarding the origin of the noise, never having had a lightweight. However, the noise being more audible when the filler cap is off is probably merely that the void acts a soundbox and removing the cap lets the noise escape.
Petrol tanks exhibit this amplification effect too.
2p

[Ozmadman]

Tell you what put a video up on you tube then we can all listen to it, I've babbled on enough, must go make my tea and do my snap for work.
Colin

Thanks, Will try when I get a mo but the engine noise/exhaust note may drown out the sound, we will see, what is "do my snap for work"?

Paul

[ajscomboman]

You can get a bit of a clatter from the points cover area due to the points cam being a loose and worn fit on the shaft of the cam gear. It clatters back and forward on the shaft, the cure is to try and make it a snug fit and ensure there is no end float.

[Ozmadman]

You can get a bit of a clatter from the points cover area due to the points cam being a loose and worn fit on the shaft of the cam gear. It clatters back and forward on the shaft, the cure is to try and make it a snug fit and ensure there is no end float.

I will check that out, thanks

[cbranni]

Food for work........Snap.........old colliers term, miners would take food below ground in a metal box, this box was called a snap tin, I was told by my grandfather that it was made by a company is S. Wales called Snap, others have told me its because the two halves of the box snapped together, so not sure, it was made in the shape of a loaf so that the sarnies didnt move about, in my family food for work has always been called "snap".

[Ozmadman]

Food for work........Snap.........old colliers term, miners would take food below ground in a metal box, this box was called a snap tin, I was told by my grandfather that it was made by a company is S. Wales called Snap, others have told me its because the two halves of the box snapped together, so not sure, it was made in the shape of a loaf so that the sarnies didnt move about, in my family food for work has always been called "snap".

Thanks, you learn something new every day..

[Ozmadman]

Thanks all, it will soon be winter so when I take the gearbox out etc I will check the timed breather stator, the points cam, the alternator rotor, check the oil pump itself whilst I can get to it, put a new guide pin in as a precaution and have a look at the cam and followers. I have had a look at the manual and it looks like you can get to the cam shaft and followers etc by just removing the points housing and oil tank, is this the case and will the push rods just drop out from there without taking the rocker box off as that part has been overhauled already?

Thanks

paul

[Ozmadman]

Tell you what put a video up on you tube then we can all listen to it, I've babbled on enough, must go make my tea and do my snap for work.
Colin

Thanks, Will try when I get a mo but the engine noise/exhaust note may drown out the sound, we will see, what is "do my snap for work"?
Paul

Here is the You tube clip, it's the knocking noise 'behind' the tappet noise. I have also showed the oil return, firstly cold and then later a drop on level as it has got warm, may be useful as this subject gets quite a bit of discussion on here and I think this is the first time someone has shown it on video..

So, what is that knocking noise??



Paul