The single cylinder diesel engine splashes very much, what s going on, the water tank still has oil

See whether it is shaking and splashing water, or air splashing water, if it is air rushing, it is the cylinder gasket or cylinder leakage.

If it's a relatively large surf splash, it's a burned. If it is a small and tall droplet, the rim of the cylinder liner is broken.

The shaking was too great.

The water tank should be cleaned.

The cooling water should be treated chemically.

Do you see any holes in the fuselage I just repaired one and changed the fuselage and there was no gas in the water.