New for 2010 is the Yamaha 25 horsepower Four Stroke. The new motor sports a 498 cc (30.4 cu. in.) two-cylinder, SOHC and single carbureted design features a new cylinder block and head with bore x stroke 65.0 mm x 75.0 mm (2.56 x 2.76 in). The pistons, connecting rods, and valves are the same as used in the F60. Full Throttle RPM Range is 5000-6000 RPM with a gear ratio of 2.08:1 (13/27) or 2.42:1 (29/12) on the High Thrust model. Their Short Shaft Tiller weighs 170 pounds and Long Shaft Power Trim and Tilt Tiller model comes in at 181 pounds. Yamaha redid their electrical system and upped the alternator output to 13.5 Amp with Rectifier Regulator.
Yamaha not only completely redesigned the inside of their 25 horsepower motor but the outside also. Their new euro design includes a compact/one-piece solid cowling design; long-span mounting system and re-shaped lower engine mount (F25S models) helping to reduce vibration for smoother operation. Also available are two tiller options. The first is their standard tiller with front mount shift. Optionally Yamaha offers their multi-function tiller handle with shift in the tiller arm.
Yamaha Motor Corporation, USA
1270 Chastain Road
Kennesaw, GA 30144
MSRP: F25SMHA $3,900 to F25LA $4,745