Check engine and lower-unit oil color monthly
Oil color tells you more than the hour meter — milky oil means water intrusion; metallic glitter means internal wear.
Why this matters
Oil color tells you more than the hour meter — milky oil means water intrusion; metallic glitter means internal wear.
When DIY is not enough
Milky oil, metal on the plug, or a sudden drop in level needs diagnosis before you run again. Our 50- and 100-hour services include fluid inspection and documented photos.
DIY steps
- With the engine off and trimmed appropriately, check the upper crankcase dipstick or sight window.
- Inspect lower-unit lube at the vent/fill screw — it should be amber to light brown, not foamy or gray.
- Smell and look for metal particles on the magnetic drain plug if equipped.
- Photograph anything unusual before your next run.
Related FTM services
- 50-Hour Service
- Mechanical Repair
Professional mobile service
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Full Throttle Marine comes to your dock in Tampa Bay and on the First Coast. Flat-rate quoted before we arrive. Yamaha and Mercury outboard specialists — no trailers, no waiting rooms.
Common questions
Check engine and lower-unit oil color monthly
Oil color tells you more than the hour meter — milky oil means water intrusion; metallic glitter means internal wear. Never ignore milky gear lube. Water in the lower unit destroys bearings fast.
When should I call a professional instead?
Milky oil, metal on the plug, or a sudden drop in level needs diagnosis before you run again. Our 50- and 100-hour services include fluid inspection and documented photos.
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Engine Maintenance
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