is my timing out??

[AnTh_VTR]

the head cracked on my 106 gti so recently put a new head on, (came off a running car) , put new cambelt, head gaskrt kit on, it drove fine for an hour or so and now it keeps cutting out. it starts but wen it rev over 3000rpm it loses all power and feels like its going to stall, then it will drive for say 5 mins then it loses all power and it just doesnt start up at all, there is power from the battery as it will turn over, when it nearly starts it backfires really loudly!
someone please help!?

[AnTh_VTR]

anyone?

[NFS]

did you skim and pressure test the head? any signs of a head gasket gone? who did the HG and head change?

[AnTh_VTR]

didnt skim it as my mate told me it would be ok as it came of a running engine. 2 of my mates did it for me, both mechanics. no theres no sign of headgasket failure

[burgerfeet]

Assuming the replacement head is ok, I would immediately check the valve timing. It is quite possible for the belt to have jumped a tooth or two especially if it has not been tensioned correctly.