How to Fix a Spun Propellerby Kevin Mclain
A spun propeller means that the prop hub has spun inside the propeller. Once the hub spins inside of the propeller, the propeller will spin freely and not along with the hub. A hub can spin inside of a prop due to damage to the hub, damage to the inside diameter of the propeller or incorrect propeller installation. Fixing a spun propeller will require the assistance of a boat propeller repair shop to press the old hub out of the propeller and the new hub into the propeller.
Inspect the propeller first to determine if the hub has spun inside the propeller. Mark the front of the propeller and the propeller hub directly across from each other with a permanent marker. Run the propeller for about two minutes and then shut it off. Inspect the two marks to see if they are still lined up across from each other. If not, then the hub is spun inside the propeller.
Pull the cone off the front of the propeller, using the pliers. Straighten and remove the cotter pin from the lock nut that secures the propeller to the propeller shaft. Place the cotter pin in a safe area.
Loosen and remove the lock nut from the propeller shaft by turning it counter-clockwise with a ratchet, extension and a socket. Pull the washer off, along with the lock nut, and place both of them in a safe area.
Pull the propeller straight off the shaft. If the propeller is hard to remove, use a rubber mallet to tap the back of the propeller until it slides off the shaft.
Take the propeller to a boat propeller repair shop or a boat repair shop and have the old hub pressed out of the propeller. Have the shop press a new hub into the propeller. The shop will also inspect the inside of the propeller for any damage.
Reinstall the propeller with the washer, lock nut and the cotter pin. Tighten the lock nut down to 15-17 foot-pounds with a torque wrench and a socket.
- " 1990 - 2001 Johnson Outboard Engine Service and Repair Manual;" SELOC Co.; 2002
- Marine Digest: Diagnose and Repair a Spun Propeller Hub
- The hub must be pressed out of the propeller by a boat repair shop or a boat propeller repair shop. If the propeller is damaged, a new propeller can be purchased from the shop.
Things You'll Need
- Permanent marker
- 1/2-inch drive ratchet
- 1/2-inch drive socket set
- Rubber mallet
- Torque wrench
- Do not over-torque the lock nut onto the propeller shaft. This will result in stripping the nut or the threads on the shaft.
Kevin Mclain has more than 20 years of automotive, home improvement and landscaping experience. He has been writing for various online publications since 2002. Mclain has U.S. Army certification in automotive maintenance and repair, among more than 15 additional certifications related to the automotive field.