Then there is the fact that the more powerful models require a large battery that is both cumbersome and tedious to keep charged and stow.įortunately, there are now a few electric motors that genuinely make the grade, including German-built Torqeedo, the Chinese-made E-Propulsion range and EP Carry. In addition, few of these smaller motors are genuinely seawater-proof except, maybe, the Minn Kota Riptide range. Yes, there are hundreds of Asian-built electric trolling motors around, but rarely do they produce more than 0.5hp. The lack of a visible indication of fuel remaining in and LPG tank can also be annoying, although as stated, changing the canister on a Lehr outboard, in particular, is quick, clean and easy.Īs with most four-stroke gas outboards, you also need to take care how you lie the motor down due to the crankcase oil.ĭespite it being over a decade since the first feasible and reliable electric outboard was launched, there are still very few that can seriously be considered a viable tender outboard. Although you can buy a special adapter that will enable you to refill the canisters from a larger propane tank when on a stable platform, this can be somewhat tricky to do and poses a fire hazard. In practice, the main downside of running a Lehr off canisters is you need to source and store (on deck or in a suitably designed locker) a large number of compatible canisters, as the specific types are not always freely available abroad. This same canister can then be easily changed out on passage. Not unlike a regular gas outboard with an integral gas tank, a 16oz canister offers around two hours of running at half throttle with a Lehr. A propane outboard also can’t be flooded the way a regular gas outboard can (and frequently does). Priced about the same, another advantage over a gas engine is that they never encounter problems with fuel quality, in stark contrast to gas, which now that it contains a large quantity of ethanol (biofuel), can block up the fuel filter and carburetor jets after a few months of use. (Lehrs can also be run using a remote canister.) Over time, propane outboards have proven to be pretty much as reliable and efficient as their gas equivalents at the same time they also emit fewer harmful exhaust gases (although they can sometimes be harder to start in extreme weather when the LPG becomes more liquid). Propane outboards are much like their regular gas counterparts, only with a different carburation setup and employing a pressurized LPG tank-either a simple screw-in canister in the case of Lehr or a larger remote bottle. Following in Lehr’s wake, Tohatsu/Mercury has also brought out a new 5hp propane outboard. company Lehr, which introduced a range of propane-powered outboards that now includes five models offering 2.5, 5, 9.9, 15 and 25hp. However, the modifications were expensive. In the past, a few companies would sometimes modify certain gas outboards to use propane.
That said, they also require laying down carefully to stop oil seepage, have more components to fail and are more complicated and expensive to service. They’re quieter, for example, less thirsty, tick over more smoothly and you don’t need to mix up large quantities of oil and gas. Despite the extra weight, a four-stroke offers certain other benefits as well. More recently, one of the biggest changes to outboards has been the move from two-stroke to four-stroke engines, in the interest of reducing exhaust emissions. They’re fairly straightforward to use and maintain, even when you’re at sea or anchored in some far-flung destination. Note the gas can inserted in this Lehr propane modelįor decades now, gas-powered outboard engines have been the best way to propel a small tender. Because of this, however, the market in older but well-maintained two-strokes is going through the roof, resulting in many of them being priced close to the level of a much newer four-stroke. This, in turn, means getting the engine onto the transom of a tender and back again can be fraught with danger-both to your back and to the engine.
Owing to the extra mechanical parts a four-stroke often weighs in at twice the heft of a two-stroke. It follows, then, that they both weigh pretty much the same, so unless there’s another good reason for not buying the higher power model (price or features maybe) you might as well grab the extra oomph without the weight penalty. For instance, most 4hp motors are the same as the 6hp version, only with restricted carburetors to lower the power.
It’s worth noting that many of the components and engines on portable outboards are the same inside, despite having different horsepower ratings. If you’re likely to be taking the motor on and off the yacht frequently, then you’ll need to compromise between power and poundage. Another important factor in deciding which size motor to buy is its weight.