Advisor contents:
    How to choose the right Power?
  How to choose the right Shaft Length?
  How to choose the right Propeller?
  Single or Twin engines ?

     Actually there are three main points to decide: BRAND NAME, POWER and SHAFT LENGTH. The question of brand name is the matter of your taste, preferences, current market situation etc. - we do not speak about it here. But we’d like to give you some information about the power, shaft length and such important issues as installation and use of the power tilt & trim.

How to choose the RIGHT POWER ?  

WHICH ENGINE POWER IS THE BEST FOR YOUR BOAT? It's a good question! Your boat has one top important characteristic: MAXIMUM ENGINE POWER ( Pmax ). It doesn't mean that you have to install only an engine with maximum power. Here we'd like to offer three most typical choices you can make and their characteristics :

Table 1.Engine power options

ECONOMICAL CHOICE - engine power is up to 60% of maximum engine power, allowed for your boat. It's really a choice of economy, safety and care to your boat. With such an engine the boat is quite slow with a full load, but performs up to 60-70% of maximum speed when it's light.

OPTIMAL CHOICE - engine power is about 80% of Maximum Engine Power.
 •  With this choice you have: Highest safety of boating,
 •  Reasonable fuel consumption,
 •  Nearly maximum performance - the difference of 10% from the maximum is not sensible at all (if you are not a racer, of course!),
 •   It sufficiently prolongs your boat life.
With this choice the boat demonstrates its possibilities in a best way.

EXTREME CHOICE - engine power is about 100% of Maximum Engine Power. With this choice the boat will work on the EDGE OF EVERYTHING: safety, performance etc. Mainly it's a way for racing and for people who love extreme situations, strong wind in their hair and usually take EVERYTHING from their life. It's really great feeling , but just in case you are strong and experienced enough to control the boat safely !!!

The use of a boat with engine power less than 40% of Max is also possible, if the performance is not important to you at all and you enjoy different things. Nature is so beautiful if not to disturb it too much!!!

POWER OVER 100%: The use of a boat with the engine power more than Maximum Engine Power allowed is ILLEGAL and DANGEROUS. Please think twice before you decide the take this way, because :
 •  it's a matter of your own life and lives of people around you,
 •  using overpowered boat you immediately loose your Warranty Coverage,
 •  you may face real problems with the Law.

    How to choose the right Shaft Length ?  
Normally the required engine shaft length is clearly mentioned in the User’s Manual of your boat. The shaft length is standard and it can be:

After the engine has been installed just make a final check to be sure if everything is correct: the anti-cavitations engine plate should be 25-50 mm (1-2”) lower than the lowest transom point.

    How to choose the RIGHT PROPELLER ?  
Mainly all outboard engine set include a standard propeller. Some engines suppliers sell them separately, so it will be a good idea to ask the engine Dealer about that when buying it. Otherwise you can be surprised! Actually it's nearly impossible to give one and exact advice about the optimum propeller you need for your boat as it depends on a lot of different things. Basicly it's a part of precise boat tuning and it's better to ask the professionals for that. If you decide to try it yourself - just follow the easy steps below:
Step 1. Install the engine, and let it work for 10-12 hours until it reaches its nominal power.
Step 2. Load the boat with a number of people you are usually going to have aboard and check the RPM number on a full throttle on top speed.
 •  In case the maximum RPM you've reached is less that Maximum RPM set for your engine - REPLACE YOUR PROPELLER WITH ANOTHER ONE WITH ONE-STEP SMALLER PITCH and check your RPM again.
 •  In case you easily reach the maximum RPM even when not on 100% throttle - TAKE THE PROPELLER WITH ONE-STEP BIGGER PITCH and check your RPM again.
 •  Try to play with propellers in order to get the best performance on full throttle, but in any case it will be better NOT TO OVERLOAD your Engine with the extremely speedy propeller (too big pitch).

For practical reasons it's better to get at least two propellers for your engine: one - for heavy load (with short pitch), and one - for boating light (with long pitch).

    Single or Twin engines ?  
Single or Twin engines ? One engine 200HP or two engines 100HP each? Which is better ?... This is a very old question, which has not just one answer. Mainly that's just a matter of subjective preference. But some things are definitely clear : two engines have MUCH MORE WEAK POINTS, PROBLEMS AND DISADVANTAGES compared to a single engine :
 •   One central internal layer: it's a reinforcement cord - cloth base, made of strong synthetic fabric,
 •   Twins cost 60-80% more,
 •   They perform slower : power equivalent of two 100HP engines is always 10-20% less than single 200HP,
 •   They are 70-80% more heavy, which becomes even more dramatic in case of 4-stroke engines,
 •   They take 20-40% more fuel, having more complicated and expensive fuel system,
 •   They are more difficult for steering,
 •   They need 2 times more space on the transom.
 •   Look at that - there's not a single serious reason to choose twins. Sometimes people can say that :"...in case of twins there are much more chances to be back safely in case something happens with one of the engines in the open sea...". Maybe in some situations it can be true, but if you look at all the list of most popular problems, which may happen, you will see that IN 90% OF ANY POSSIBLE SITUATIONS THE PROBLEM WITH ONE ENGINE IMMEDIATELY CHOKES THE SECOND ONE. For example : any serious problem with the fuel system (water, mechanical damage, etc), steering system, electric & control system suppresses both engines, one by one.
The most well known advice in this situation is : YOUR INVESTMENT TO HIGH-QUALITY VHS-RADIO CAN BE MUCH MORE EFFECTIVE AND HELPFUL TO YOU INSTEAD OF THE SECOND ENGINE. It can be even a regular cellular telephone, if you are in costal waters !!!

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