Draining a Flooded Engine

Guide

Draining a flooded engine

Difficulty: Intermediate Time: ~15 min Applies to: Gas boards Last updated: Sep 2026

Watch the walkthrough

Watch on YouTube ↗ · JETSURF troubleshooting. Timestamps in the steps below follow the video's on-screen counter (0:20–2:36).

Symptoms

Engine won't start; the starter cranks it over normally
The spark plug is wet with fuel when you pull it
The board is showing a fault signal

Tools & supplies

Spark plug wrench (included with every JetSurf)
Magnet (to trigger the cleaning sensor)
Board stand
Clean, dry rags

Steps

0:20 — Remove the spark plug cap and unscrew the spark plug from the engine.
0:38 — Put the board on the stand with the cylinder facing down. Turn the jet pump by hand to push water out — don't crank it out on the starter.
0:38 — Hold a magnet close to the cleaning sensor.
0:50 — That activates cleaning mode, which ejects the water from the cylinder.
1:01 — Dry the spark plug, thread it back in by hand, then back it off two turns.
1:08 — Start the engine briefly to blow out any remaining water.
1:44 — Pull the spark plug again and dry the whole combustion chamber and the plug.
2:11 — Refit the spark plug, tighten it with the wrench, and secure the plug cap.
2:36 — Try starting the engine again.

Tip: backing the plug off two turns before that first restart (step 5) lets water and vapor escape past the threads instead of hydro-locking the cylinder. Re-seat it fully once the engine has cleared itself.

Caution: never keep cranking a flooded engine on the starter to clear it — water doesn't compress, and you can bend the connecting rod. Turn the pump by hand and use cleaning mode. If the plug comes out wet again after a full dry, stop and check what's flooding it. See Spark plug check & replacement for reading plug condition.

Draining a flooded engine