Engine knocking & won't start, know what it is?

[Scuba_Steve]

Ok hopefully someone might be able to help out. I'm not having a successful time at the mo, I've got both my road bikes off the road (yay more xmas bills ) 1 I'm fine with just need parts & I can get her going again, but the other one (my Viffer) well she cut out on the way home the other day & wont start back up.
Was cruising along quite happily when she just cut. Nothing! she was dead. Since then she won't start again. I've checked some basics, like electric's appear to be all working, fuel is getting through to carbs etc but she just doesn't start & shes making a knocking sound from the engine, this is very well the problem, so I'm hoping someone might recognize the noise & have an idea of the problem at hand.
This YouTube is of the sound & a photo of where the noise appears to be coming from

[blackdog]

Is the VFR bald eagles old one? Because he had the same issue with it... ask him what it was.

[Scuba_Steve]

Is the VFR bald eagles old one? Because he had the same issue with it... ask him what it was.

tis indeed, cheers I'll try him too.

[MSTRS:Me]

Perhaps to really hear a knock, one must be in front of the actual bike?
But, from what I can hear, it sounds like a lack of compression.