If you rev a jetski in reverse will it flood the engine?

Question

my friend has some jetskis, and we were on them the other day, some of the kids traveled fast forwards and then used reverse (high revs) to stop they also submarined them twice. which one of these would cause the jet ski engine to flood or would they at all?

they were never capsized but the engines are now flooded, what else could cause this?

Answer 1

You're friend needs to stop allowing non boating safety educated people on the PWC's that do not drive responsibily.  Such reckless behavior by using reverse as a hard brake for high speed is very dangerous, destructive to the PWC, and could injure or kill the occupants.  If a non-family member was allowed to drive or be a passenger of this being done and someone was badly hurt or a death occurred, the PWC owner could be sued and potentially face criminal charges or fines.

Switching to reverse while moving forward more than 6 to 8 mph puts heavy stress on a boat or PWC's drive system.  It can also flood the exhaust system for some boats or PWC's and potentially do expensive damage to the engines.

I recommend you do a serious hard talk on this to your friend and explain that allowing this can cost you a LOT of money in repairs, ruin your day, and have legal action brought against you (civil, criminal).

Answer 2

If the ski is stopped, it will just go backwards as it lifts the stern (from the direction of the forced water).

When they are submarined, water enters the hull and if they are not ridden around for a bit to pump out the water they can fill to the point that the motor sucks water and hydrolocks.

Simple solution is to pull the plugs of the motors, then crank them to blow out all the water. THen replace the plugs. Oh and disconnect the lever for the reverse function or remove the deflector on the jet so that they can't go backwards anymore.