engine idles fine, but sometimes when try to get on plane it will shutter and not go past 2000 rpms. back off throttle and try again and it may pop up great or still shutter. changed water filter and plugs, new gas and no clue what to do now?
When it is not running properly, use an inductive timing light to check the spark pulses on each of the 6 plug wires. See if you have good fire on all of them.
