Technical punto 75sx wont go above 3000 revs

[punto75sx]

still having problems with the punto not back on the road yet not had much time to fix anyway it recently had a new head gasket and head skimmed had trouble timing up but got that sorted it fires up first time every time but it idles spot on but when you go to drive it it wont go above 3000 revs even if its just psrked up it wont rev above 3000revs its had new plugs new thermostat no air locks any ideas guys dont wana throw much more money at it