can some 1 explain please

Its hard on the outdrive gears, coupler, engine, ect.... When the engine free revs then you re-enter the water it give everything a big jolt. Think of it as spinning your tires on the ice then hitting dry pavement.

Think of it like going down the road at full throttle in your car, then throwing the shifter into neutral with your foot still to the floor, and then dropping it back into gear again. When you put it in nuetral, the engine will redline (possibly blow if you dont have a rev limiter) and then slam back into gear, possibly damaging the transmission, u-joints, rear axle, etc.

So bottom line, if you like your engine and outdrive to be in working order, dont do that.

As long as your props stay in the water.......nothing wrong....my sonic crashes and splits waves more than it gets on top of them. Very rarely have to throttle a wave

Come up to lake michigan some time. 47 Apaches have to work the throttles some days up here.

Lol I went out on a fishing boat up there on what he called a calm day..... we were in 3 footers and told me they get 10+... I will stick to loto and kyl

the wave isn't the issue...it's getting the props out of the water.
Like stated, lift the rear of your car off the ground, run the tires up to 60mph, then drop it on the asphalt.......after a couple of those something is going to break.

Drivetrain loading is extremely harsh when a boat completely leaves the water, and is allowed to rev beyond the "in water" speed before re-entering the water.

When the first Yamaha Waverunners came out, they used their 500cc outboard motor powerhead as the base for their Waverunner motor. The motor in outboard motor form was considered bulletproof.

Waverunners, though, are "in and out" of the water all the time, loading and unloading the drivetrain. Yamaha did put a tight rev limiter on the motor when converting it to waverunner duty, but they underestimated the cyclic loading issues.

The result is that the first-year waverunners were experiencing a huge number of broken crankshafts.

Yamaha covered them all under warranty, and beefed up the crankshafts. The 500cc versions were subsequently phased out for the 650cc motors which were designed from the start to be beefier for the PWC application.

MC