Took my ar for a blast and it seems to be flat at high revs like the power valve isn't working. So I have had the cover off and it operates when I rev the bike I have been through all the faqs and a lot of the site but still dont know. Also the headlight is not working but the full beam light is lit up on the clocks and when I indicate both front ones flashed together so now I'm thinking ecu nightmare! Cheers for any help chaps steve

Multi meter time, sounds like the spaghetti behind the headlamp nacelle has had a shake up.
Try a new plug plug for starters.
You may have to remove the exhaust to verify the valve is lifting fully.
Mike

Cheers Mike that will be my next job one night after work then

The lack of top end response is [sometimes] accompanied by different exhaust note when the throttle is opened and,it's then generally the ECU that's at fault. Flicking the ignition off and on, can reset the ECU, but generally it's best taken as an early warning that some expensive repair work is about to surface.
Mike

I've got a multi meter to use at the weekend I'm wondering could I put the ecu on a good running bike to find out if it is the problem? Or could I risk breaking something on the good bike don't think I should just put a good ecu on the faulty bike without knowing what may have blown the ecu in the first place

Test yours on a known working bike is the way forward, the reverse may be costly.
You can also check circuit readings for general similarities at he same time.
Having looked in the search area, you will no doubt know that a malfunctioning REG/REC can kill the ECU stone dead, and seized P/V cables will also give the unit a coronary.
Mike

FMtB +1

Cheers guys all advice is been taken on board. I tried my ecu on another ar and that ran spot on with no faults so good news on that side but still need to find the problem. Also took the reg off and checked for heat bubbles but that looks fine so I think as Mike recomended multi meter time at the weekend and see if I can find a problem