Motor bucking bad when throtle up

[Baileys Boat]

Last outing motor bucking when going from 3,000 RPM to full throttle. It cleared up and had no problem rest of weekend. Put boat back in water and motor bucking when I go to full throttle and wont get better. Changed fuel filters, cleaned plugs, changed gas lines, changed gas tank to mix to see if bad fuel or water and still consistantly the same. I can get to plane at 3,000 RPM but when I full throttle the motor bucks bad. When I back it of to 3,000 again it runs smooth as silk. Idles great as well. Any suggestions on further checks. Thanks

 

[fireman 757]

Re: Motor bucking bad when throtle up

Don't know what to tell you as you never said what kind of engine you have. If it is an outboard I would check your ignition coils.