Thinking about running a Yamaha 25 hp on a small aluminum rig and trying to set realistic expectations for top speed. I’ve seen everything from 20 to 30+ mph claimed online, but it sounds super dependent on hull, load, prop, and setup. For folks actually running a 25 (two‑stroke or the newer F25 four‑stroke), what GPS top speeds are you seeing and what setup gets you there?
A few specific questions:
- What’s a realistic top speed on a 14-16 ft jon/utility/semi‑V with one person vs two, light fishing load?
- What WOT rpm range should I be targeting on the Yamaha 25, and which prop pitches tend to hit it on common hulls?
- How much top speed did you gain (or lose) from engine height changes (moving up holes, jack plate), trim, or switching from aluminum to stainless props?
- Do cupped props help with holding trim without killing speed on these small motors?
- Any noticeable speed change from adding a small hydrofoil or smart tabs, or do they mainly help hole shot?
- Altitude: how much does it knock off on a 25 hp in your experience?
If you’re willing, could you share your numbers in a quick format? Trying to build a little real‑world reference:
- Boat make/model/length/hull type
- Approx boat + load weight
- Yamaha model/year (2‑stroke or F25 4‑stroke), tiller vs remote
- Gear ratio if known
- Prop brand/material/diameter/pitch/cup
- Engine height (holes up or jack plate setback/height)
- WOT rpm and GPS speed
- Elevation and typical load (people/gear)
- Any handling notes (porpoising, ventilation, chine walk)
Not chasing a unicorn speed, just want a solid, safe setup and a realistic top-end target before I buy.