Vibration and noise

I don't get the noise in neutral no, and yes it is Hitachi

Correction, I do get the noise in neutral. Also if I am going in say second and the noise starts as I get to the upper limits of the gear, if I change to third it then disappears until I get up to the same sought of revs.

Well, the flywheel can't be the cause there (as long as the flywheel itself and the cranck is in good condition) since this flywheel doesn't have the retard / advance mechanism.

Because the problem occurs in neutral as well, the cause should be somewhere in or around the engine.
Bad timing / worn plug or coil / fuel mixture / valve clearance, but mostly worn washers or bolts to hold the engine in the frame.

Cheers Waynus. I am going to have a look at my timing this evening and the valve clearance. Do you know where i can get details of what the various clearance dimensions should be and possibly instructions on the adjusting of these. I have them in a CT70 manual but am aware that these may vary for my bike?

No, it should be the same. 0.05mm
This should help you http://www.youtube.com/watch?v=HppcqVpn ... annel_page

Have now checked the timing and valve clearance and all seemed well and good there, made a minor adjustment but not much. Still getting the noise and vibration. It almost feels like something is rubbing and like something that is rotating. May have to concede on this one and get the garage to take a look.

I'll come over to celebrate christmas in London and have a look at your engine .
Sorry, I can't give you anymore thoughts on the problem without having a look at the engine and hear the vibrations.
If the garage finds out the problem, make sure you let us know!

No problem, you have been a great help with many things, if not directly then via old posts. I will be taking it to the garage in a week or so and will let you know what the problem is.

So before taking the bike to the garage I decided to revisit the various things that Waynus had suggested to me it could be and low and behold he had it spot on. It was the engine mountings all along. I did them up real tight, which I thought I had done already, and the sound has now completely disappeared. Cheers Waynus, one happy ST70 owner here. I will get a few pics of my bike up soon for all to see.

Good news! Glad you were able to solve this matter yourself.
It's wise to check the condition of all these washers, nuts and bolts from time to time and replace the when needed.
Especially the washers are required in order to prevent damage to the frame when tightening these up.