timing please please help me

[matthg40]

evening all my head gasket went a while ago so ive changed it and put the engine back together and its running like a bag of s**t.Ive timed it all up to tdc on idle so it ticks over perfect, however when you rev it, it retards back quite abit so i took it for a run round the block and it doesnt respond at all its doesnt pull or anything does any one have any ideas wot ive done wrong if so please help me thanks all p.s forgot to mention i brought a timing strobe

[hayesey]

have you set the ignition timing with a timing light?

[matthg40]

yer forgot to mention that brought a timing strobe from parkers