Perhaps I need to rotate the airplane more quickly.
The rotation
rate should be
less than the normal four-engine rate which will then allow the airspeed to increase towards V2. Do remember, however, that when you have "positive climb" and you then select the gear UP there will be a temporary increase in drag as the gear-doors open. This will require a small adjustment in pitch so as not to allow the airspeed to reduce; with practice, you'll anticipate these small variations in pitch as you become more accustomed to the aeroplane.
If you're operating with reduced thrust, it shouldn't be neccessary to increase the thrust towards maximum... unless, of course, it's all going wrong!
Hold it on the runway a touch longer so your rudder input is just right before you rotate.
When operating at the higher end of the weight schedule this might not be an option (high ambient temperature & pressure altitude/limiting runway)... is there enough tarmac/concrete in front of you?
Chin, chin
TCF