Help horrible vibration!!

[Jpaul]

I have a 94 Sea Rayder 90 hpwr with a horrible vibration. Happens as soon as you start the boat both in the water and on the trailer. Compression is good across all 3 cylinders, I also pulled wires while running and it made no difference and put in new plugs as well. Carbs were recently cleaned as well. The thing runs and sounds great just has this vibration that shakes the whole boat and anything in it. Checked the shaft and impeller nothing is stuck in there. And the gear oil is full and clean. Vibration does not go away while on plane and the boat will go up to 35 mph no problem. I have no clue where else to look. Any suggestions would be great.

 

[Julian]

I'd look at:

1. Motor mounts
2. Engine to pump coupler
3. Pump itself (if you pull the pump does it still vibrate). But pull the pump regardless to confirm 100% there is nothing in it.