Essential Tools and Parts
Before commencing the 100-hour maintenance on your Yamaha F115, gather the following tools and parts:
- Drain pan
- Oil extraction pump
- Filter wrench
- Socket wrench with 10, 12, and 14 mm sockets
- Spark plug socket (5/8" or 13/16")
- Pliers
- Protective glasses
- Oil funnel
- Shop towels
- Oil absorbent pads
- Rubber gloves
Preparation
Position your boat on a non-porous surface like concrete to prevent environmental contamination from spills. Ensure all tools and parts are within reach, and wear protective gear to safeguard against chemical exposure.
Spark Plug Inspection and Replacement
Begin by removing the spark plug caps and using the spark plug socket to extract each plug. Inspect for signs of wear, carbon buildup, or overheating. Replace any damaged plugs with NGK spark plugs, ensuring they are pre-gapped as specified. Reinstall the plugs, tightening to 18 ft-lbs of torque, and reconnect the spark plug wires securely.
Oil and Oil Filter Change
Utilize the oil extraction pump to remove old engine oil via the dipstick port. Once drained, remove the old oil filter using the filter wrench. Apply a light coat of fresh oil to the gasket of the new filter before installation. Refill the engine with 10W-30 oil, unless operating in extreme temperature conditions, where 20W-40 may be appropriate. Check the oil level with the dipstick to ensure proper fill.
Fuel-Water Separating Filter Replacement
Remove the existing fuel-water separating filter, catching any residual fuel with a rag. Lubricate the gasket of the new filter with marine grease and install it by hand, avoiding over-tightening to prevent seal damage.
Fuel Filter Maintenance
Inspect and replace the following fuel filters as necessary:
- Primary Filter: Typically a translucent housing with a replaceable element.
- Lift Pump Outlet Filter: A mesh-style filter located near the lift pump outlet or fuel VST.
- VST Filter: Attached to the inlet of the medium-pressure electric fuel pump inside the VST.
- Injector Filters: Require specialized service; consult a professional technician.
Fuel Additives and Lubrication
To mitigate the effects of ethanol in fuel and prevent corrosion, regularly use fuel additives like Ring Free. Spray the powerhead and electrical components with T-9 to protect against rust. Apply Yamalube Marine Grease to all zerk fittings, including those on the mid-section and steering tube, to ensure smooth operation.