Thanks Flyingscott
Make long story short, here goes
Motor runs great to approx 3500 rpm then when going toWOT motor has sporadic instantaneous cut out, a milla second or so, dyes then back to life. Enough that skier can feel it and it is noticed with sound of motor change.
Have had wire harness from stator changed, carbs cleaned and synced, new plugs, new fuel line from tank to motor. Mechanic checked fuel pump accelerator and throttle cam, all ok.
Recently I was looking at wires bundle from stator and found a loose bullet connector, had this replaced when motor was being readied for winter storage, so cannot determine if this could have some bearing on the problem till spring when boat goes back in the water.
During all work at the shop motor performed great on the dyno with loads to WOT.
Anyway thanks for your input and would be grateful to any other ideas or suggestions to ponder during the winter and then check out in spring.
As for Carbs, all input has lead me to decide to leave as is and look for other electrical issues.
The cut out is so quick and intermittent that it is leading me down the electrical issue path.
One other issue is that when coming down from WOT to Idle after running across the water, the motor makes a rattling sound.
Motor idles smooth and great hole shot. the issue of cut out only happens after boat reaches plane and then trying to get up to full 5250 rpm.
You can see the cut out on the rpm Gage drops from about 5200 down to 4800.
What issues are you having? The bottom 2 carbs are different as they have accelerator pumps on them. I have had the accelerator pumps on them fail and start leaking. This causes the bottom 2 cylinders to start firing they start to idle very rough when that happens not pleasant. I would leave it alone because if you start to modify the motor it could cost you a motor. Your max RPM for that motor is 5250 not 5450. I also don't believe that carb has an idle circuit cast into it at all you would need to buy 2 top carbs.