Mercury force 120 out board boat engine.?

Question

as soon as you get on the throttle you have about 10 minutes before the plugs file out we replaced them and it did it again. for about 1/.4 mile it tries to level out but looses *** power, misses uncontrollably, smokes as well. if anyone can give us any ideas of what to look at we would greatly appreciate it. p.s the last owner claims the engine was recently rebuilt. i can confirm it was taken apart but not rebuilt, thanks so much

Answer 1

will not start..cranks over,have spark 135 psi all cylinders,pumps cleaned,timming ok..??? Gas flow Ok.