New 25hp four-stroke LPG outboard

One of the more interesting innovations in marine engines released at the 2015 Miami International Boat show earlier this year was a new 25hp propane (LPG) outboard by clean-power innovator LEHR.

The American company unveiled its new clean, efficient 25hp outboard engine to complement its existing 2.5hp, 5hp, 9.9hp and 15hp range. Like any portable outboards in this class, the four-strokes are suited to propelling a range of small lightweight craft, pontoon boats and even houseboats.

The 25hp model uses a two-cylinder, 498cc SOHC four-stroke engine. LEHR’s most powerful engine to date, and the largest factory propane outboard available, is also said to boast some real advantages exclusive to propane or LPG outboards.

These advantages include easy electric or pull starting (with no troublesome choking or priming), maximum acceleration/performance with 110-octane fuel and superior efficiency that delivers more miles (and boating fun) between fuel stops. Plus big enviro benefits.

ZERO EMISSIONS
The LEHR propane or LPG outboard produces zero evaporative emissions and no marine pollutants, LEHR says.

"We’re very excited about our new 25hp model and what its introduction will mean to the boating industry worldwide," said Capt. Bernardo Herzer, CEO and founder of LEHR.

"As we continue to expand our line, more boaters will experience the benefits of propane [LPG] power and will realise that great performance and doing great things for the environment can go hand in hand," added Herzer.

HOW IT WORKS
An innovative Liquid Draw fuelling system is key to the LEHR 25’s performance. The specialised liquid draw tanks work in concert with an innovative heated evaporation system that rapidly changes the state of the fuel from liquid to gas.

This unique fuel delivery system, which includes rugged stainless steel fuel lines, prevents the fuel from freezing and ensures a steady, precise supply of vaporised propane to the engine.

The new LEHR 25 is said to be engineered and built for long-term
performance and reliability in the harsh marine environment, with
stainless steel drive, shift and prop shafts and corrosion-resistant
materials throughout.

All LEHR outboards are backed by the company’s 3-Year Warranty, which includes the optional internal Lithium Iron battery.

TECH TORQUE
An optional internal, fully sealed Lithium Iron battery is available on Electric Start models.

The lightweight (<1kg) battery integrated into the engine simplifies rigging and saves valuable deck space.

To accommodate a range of boat styles and applications, the LEHR 25 is available in 15" (S) and 20" (L) shaft lengths with various options for Manual/Electric Starting, Tiller/Remote control and Power Tilt and Trim.

The LEHR 25 is offered with optional 10kg tank or 14kg Liquid Draw Composite Tanks designed for marine use. These lightweight tanks feature an opaque design that allows boaters to see at a glance the amount of fuel inside.

Several other tank options are also available, including aluminium and steel tank options in a range of sizes to suit the needs of a variety of boats.  The smaller models (second photo) can accept an LPG bottle straight into the cowl. Or just use a 9kg bottle or Swap and Go with a lead!

LPG CONSUMPTION
Considering the fuel-efficient characteristics of the LEHR 25 — recent testing showed consumption rates of 4.16lt/hr at 3000 rpm and 9.5lt/hr at 5000 rpm — boaters should have plenty of time to explore, fish or cruise between fill-ups.

With no petrol to clog the carbie or fuel lines, there is no need to run the motor dry at the end of the day. Nor is there any need to winterise the outboard before long periods of storage.

The new LEHR 25 Propane Outboard is scheduled for public availability beginning May 2015 through West Marine retail centres in America and other LEHR outboard dealers across the U.S. and Canada. MSRP for this new outboard will begin at US$4295. No word on a local dealer. Yet.

Specifications
Engine Type: Propane-Powered 4 Stroke SOHC
Horsepower Rating: 25hp (18.4 kW)
Displacement: 30.4 cu in / 498 cc
Bore X Stroke: 2.56? x 2.95? /65mm x 75mm
Cylinders: 2
Full Throttle RPM Range: 4500-5500 RPM
Ignition System: CDI Ignition
Starting System: Manual or Electric
Fuel: Propane (110 Octane)
Carburetion: No Choke / No Priming
Lubrication: Wet Sump / Pressure Lubricated
Control System: Tiller Handle or Remote
Exhaust System: Through Prop
Cooling System: Water / Thermostatic Control
Trim Positions: 5
Gear Shift: F-N-R
Gear Ratio: 2.08
Alternator Output: 6 amp / 80 watt – Electric, 6 amp / 80 watt – Manual (requires optional regulator)
Shaft Length:  15?(S) &  20? (L)
Standard Prop: 8? x 8.5?  3 Blade Aluminum
Weight: 172 lbs to 194 lbs
Fuel Tank Type: (Optional): 22 & 31 lb Liquid Draw Composite Tanks
Recommended Oil: 4 Stroke 10W-30
Engine Oil Capacity: 0.53 US qt (0.5L)
Warranty: 3 Year Limited Warranty
C.A.R.B. Rating: 3 Star Ultra Low
www.golehr.com