2000 wellcraft 3000
 

sometimes after starting the starbord motor I hear a thump thump and feel it
in the stearing wheel and sometimes will shake the boat all of the items
happen at the same time so I turn off the motor and restart and most of the
time it wont happen again but it may take 2 restarts. this has only happened
on cold motor starts the motors are volvo 5.7 carburated.