0587041 EVINRUDE ENGINE HARNESS Assy

Rating Definitions
The Caterpillar marine propulsion engine rating definitions are:* A - Continuous Duty-For heavy duty use with little load cycling (throttle operation up to 100 percent of total time) in oceangoing displacement hulls such as freighters, tugboats and bottom-drag trawlers, and deep river towboats. Expected usage is 4000 hours per year or more.* B - Medium Duty-For use with full throttle operation up to 80 percent of total operation time with the balance of time below rated rpm in midwater trawlers, purse seiners, crew and supply boats, ferry boats with trips longer than one hour, and towboats in rivers where locks, sandbars, curves or traffic dictate frequent slowing. Expected usage is 4000 hours per year, average, is typical, but could be higher.* C - Intermittent Duty-For use with full throttle operation up to 50 percent of total operation time with the balance of time below rated rpm in yachts with displacement hulls, as well as ferries with trips less than one hour, fish boats moving at higher speeds out and back (e.g., lobster, crayfish and tuna), and short trip coastal freighters where engine load and speed are cyclical. Expected usage of up to 3000 hours per year, average, is typical.* D - Patrol Craft-For use in patrol, customs, police and some fire boats. Also for bow/stern thrusters. Full throttle operation up to ten percent of total operation time with balance of time below rated rpm. Expected usage is less than 2000 hours per year.* E - High Performance-For use in pleasure craft with planing hulls, as well as for pilot, harbor patrol and harbor master boats with full throttle operation up to five percent of total operation time with balance of time below rated rpm. Expected usage is 200 to 300 hours per year. Some fish boats operate on duty cycles where D or E engine ratings apply.Time at full throttle is the cumulative time the engine is operated at full throttle load and speed during a work cycle, duty cycle, or voyage.These rating definitions dictate the selection of a rating for an application based on a load profile determined by time at various throttle settings or engine speeds. In general, an application requiring less time at full throttle, or lower engine rpm at reduced throttle operation, can utilize a higher rating.Application Guidelines
In selecting a rating for a specific application, the most important consideration is time spent at full throttle. Additionally, these rating definitions identify percent of time at full throttle and corresponding times below rated rpm. This rpm reduction lowers kW (horsepower) requirements as propeller demand follows a cubic speed/power curve.For example, an engine operating at 90 percent of rated speed would be loaded by a typical propeller to about 73 percent of rated power. Operating at recommended reduced speed controls the engine load at or below the continuous power level.As a general guideline, typical operating parameters for each rating level are summarized in the following chart. For more information, refer to your Caterpillar dealer and EDS 108.0 in the Caterpillar Technical Manual. The above rating definitions assure the customer obtains an acceptable and competitively priced match between initial cost and total life and lifetime costs.When operating the engine in an application consistently requiring more time at full throttle than the designated level, higher maintenance costs and premature wear of the engine will be encountered.Users of intermittent and high performance ratings will normally use a reduced engine speed below the suggested reduced engine rpm. Fuel consumption at the suggested reduced rpm is at or near the engine's optimum fuel efficiency. Reduced engine rpm refers to operation of the engine at speeds at or below the specified percentage of reduced engine rated speed. The chart lists the reduced engine speed operating parameters.Ratings Versus Applications
Ratings should be applied on the basis of vessel operation. It is incorrect to assign a rating to an application based only on the type of boat or hull design. Vessel descriptions such as workboat, fish boat, or ferry boat and hull design such as displacement or planing hull do not completely define the operating conditions of the vessel or the power demands from the engine. These descriptions could have more than one rating applied, depending upon how the vessel is operated.For example, the application of a vessel as a passenger ferry does not indicate a specific rating should be used. A coastal ferry boat is operated for extended periods at full throttle for long runs with short intervals at reduced throttle for maneuvering and docking. Annual hours of operation are high. Application of a lower level rating is indicated.Another ferry boat has a short run across a river requiring much shorter periods of full throttle operation. Annual hours of operation are low due to seasonal operation and weekly schedules. A higher level rating would be appropriate.Other examples of vessel applications that could have a choice of ratings, depending on their individual operating profiles are:* Lobster Boats* Crab Boats* Patrol/Police Boats* Search and Rescue* Harbor Tugs* Shuttle Tugs* Crew Boats* Fishing Trawler* Supply BoatsIt is important to know how the boat will be operating, so the rating can match the operating profile. Additionally, it is important that the proper rating is selected so the customer's perception of price/value is realized.For most applications, the customer can provide profile information from similar vessels or the actual vessel, if repowering. If such information does not sufficiently indicate the operating profile, instruments are available to more precisely define engine operation. A recording tachograph (7D1513), available from Caterpillar parts departments (or commercially), can establish an operating profile. It records engine speeds versus time on a paper chart.Engine Power Ratings
There are two general power ratings for marine engines: intermittent or continuous. These ratings are the recommended engine power settings based upon load requirements and type of operation.
Power settings should only be made by authorized personnel.
Intermittent Rating
Power settings for this rating allows the engine to be operated at full load and speed for periods up to one hour, followed by an equal