The propeller diameter is the distance between the imaginary circle that wraps around all the propeller blades.

Pitch is the theoretical distance a Honda propeller travels with each rotation. For example; a 21 boat screw pitch would be a boat at each rotation 21 inch (2.54 x = 53.34 cm) have to move on, assumed that there is no slip What is the difference between a left-turning or dextrorotatory Mercury <screw?/h4>

In most cases, in boats with a single outboard engine a right-handed screw used. Linksdraaiende propellers are used in the Assembly of double motors for better handling characteristics.

How do I choose my boot screw?

By default, a Mercury outboard motor comes with a so-called standard screw. This one is so chosen that he meets in combination with most boats behind which the Mercury Outboard mounted.

The most important factor for the match between the Mercury outboard motor and the boat is the pitch of the propeller. That determines the ratio between the engine speed and the speed of the boat. The pitch is the distance a propeller moves when he finds himself one rotation by the water "unscrew". A boat screw with flat blades made a short distance. If the sheets are placed schuiner is that distance is greater. In a comparison with the data of a car can say that the boat at a small prosperity in a lower gear than if the propeller is a matter of urgency. That affects the speed of the boat at an engine speed, but also on

the pull.

Om to choose the right propeller must first be measured whatever speed the engine is running at top speed. Then the speed recommended by the manufacturer in the work area. Usually that's anywhere between 5000 and 6000 RPM. It is recommended also to measure the top speed with a GPS.

You go for a maximum speed, then the engine speed in the direction van the maximum value within this area. The measured speed is lower than the indicated operating range then there should be a screw with a smaller emergency boat. After mounting the new prop will be the top speed achieved more quickly: the pull is at the same time larger. In addition, the top speed despite the smaller prosperity often slightly higher, because the outboard engine in its optimal working speed. Of course, after changing the propeller always check if the outboard motor at top speed in the specified rows. Conversely, a boat screw with greater prosperity the solution when the engine at top speed makes too many revs.

The table below gives roughly to the impact on the speed as the pitch of the propeller. This is related to HP-class of the Mercury Outboard <./p>

Number Of Hp	Difference in prosperity between the Mercury Screw	Speed difference per measure
300 HP	2 inch	500-600 rpm
200-250 pk	2 inch	500-600 rpm
70-175 HP	2 inch	500-600 rpm
40-60 HP	1 inch	350-450 RPM
8-20 HP	1 inch	500-600 rpm

 

That also means that the choice of the emergency depends on the intended use of the boat. If the boat is only used to quietly revving it might be more comfortable to a propeller with a slightly larger prosperity to choose (1 size larger). The engine speed remains lower, the boat is more economical and the buitenboordmotor engine is quieter.

Conversely, it can be useful for water skiing to choose a smaller emergency: the outboard motor then turns more revolutions and has more pull. The top speed is limited because the outboard motor at its maximum driveental is bounded.