4 stroke won't ramp up past 4k

[kspike]

I've got a 2004 Merc 60hp Bigfoot efi that doesn't accelerate past 4k rpm without hesitation, i've replaced the low and high pressure fuel pumps along with the regulator, also emptied gas tank to eliminate any water and still not running right, any ideas?
Thanks

 

[QBhoy]

I've got a 2004 Merc 60hp Bigfoot efi that doesn't accelerate past 4k rpm without hesitation, i've replaced the low and high pressure fuel pumps along with the regulator, also emptied gas tank to eliminate any water and still not running right, any ideas?
Thanks

Is the gas tank a remote or built in tank ? If the latter, did you check the pick up pipe was clear and not gathering crap on it ? Can often attract crap and block when under high load demand for fuel…there may be a non return valve in the line too that can get blocked.
If a remote tank…did you check that the line isn’t drawing air or that the primer bulb is set the right direction (there is a wee arrow to show this on it). There may well be a small filter on the fuel system on the engine too. Wee mesh type. Depending on age.