My dynamo has slight play when you grab the pulley wheel in and out but no play up and down, is this ok ? . I ask as my ignition light is on at start up but then goes out as normal but starts flickering at higher revs flickering matches engine revs then goes out at idle.my voltage dial reads just over 12v at idle and over 14 at revs. Ive fitted a new regulator and checked dynamo at the terminals with volt meter at revs the meter was reading around 70 to 80. My battery sits behind drivers seat when light flickers at revs i can hear a ticking sound behind me matching revs and light flickering speed. Confused 

A little bit of play is fine. It sounds like the commutator is a little out of true or just dirty causing the brushes ( I assume you've checked the brushes and they're okay) to bounce a little at speed.

A little bit of play is fine. It sounds like the commutator is a little out of true or just dirty causing the brushes ( I assume you've checked the brushes and they're okay) to bounce a little at speed.

I replaced the brushes and cleaned the commutator with emery cloth

After cleaning the comm up did you clean out the gaps between the segments to stop shorting..

After cleaning the comm up did you clean out the gaps between the segments to stop shorting..

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Yes cleaned them out with a blade. Could it be bad earths or worn brush retaining springs im at a loss

could be a faulty regulator new does not mean correct these days. the only other thing is the brushes bouncing and away from the comm.

Check that cleaning with emery cloth has not clogged the gaps between the commutator with conductive filings   

I usually clean the comm gaps out with a sharp ice lolly stick, nothing metal/conductive.