Water would not enter through the spark plugs. Watet would enter through the Exhaust or Intake.
Water will also enter crankcase, rear differential, driveshaft, Transmission via breather's.
Airbox - Carborator tube all depends on how the bike was laying submerized in the water.
Should now drain all fluids to check for water. Do not try to start a bike that is submerged in water - pull the plugs and diperse the water out of cylinders.