Section 7

DIAGNOSTIC TESTS

4.Crank the engine rapidly. Engine must be cranking at 350 rpm or more. If spark jumps the tester gap, you may assume the ignition system is working properly. Repeat on remaining cylin- der spark plug.

5.To determine if an engine miss is ignition related, connect the spark tester in series with the high tension lead and the spark plug. Then, start the engine. If spark jumps the tester gap at regular Intervals, but the engine miss continues, the problem may be in the spark plug or fuel system. Repeat on remaining cylinder spark plug. Proceed to Test 33.

6.If spark jumps the tester gap intermittently, the problem may be in the Ignition Magneto. Proceed to Test 34.

Figure 7-32. – Testing Ignition System

Figure 7-33. – Checking Engine Miss

RESULTS:

1.If no spark or if engine miss is apparent, go to Test 34.

2.If ignition spark is good, go to Test 33.

CYLINDER BALANCE TEST:

If the engine is hard starting, runs rough, misses or lacks power, perform a cylinder balance test to deter- mine whether both cylinders are operating to their full potential.

Tools Required:

1. Two Ignition Testers (Generac P/N OC5969)

Attach an ignition tester between the spark plug lead and each spark plug (Figure 7-33).

Start and run engine running at top no load speed and note spark at ignition testers. If the spark is equal at both ignition testers, the problem is not ignition related. A spark miss will be readily apparent. Now note RPM of engine. Ground out one cylinder by con- tacting ignition tester and a good ground on engine (Figure 7-34). Note RPM loss. Then ground out the other spark plug and note the RPM loss. If the differ- ence between the two cylinders does not exceed 75 RPM, the amount of work the two cylinders are doing should be considered equal.

If the RPM loss is greater than 75 RPM this indicates that the grounded cylinder with the least RPM loss is the weakest of the two cylinders. Look to that cylinder for a problem.

Example:

Engine RPM - Both Cylinders = 2570 RPM

Engine RPM - No. 1 Cylinder Grounded = 2500 RPM Engine RPM - No. 2 Cylinder Grounded = 2300 RPM

Conclusion: No. 1 cylinder is weakest of the two cylinders.

Figure 7-34. – Cylinder Balance Test

The cylinder balance test will also detect a cylinder that is not functioning. When grounding out one cylin- der there will be no RPM loss. When the other cylin- der is grounded out the engine will stop.

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Generac Power Systems 55, 75, 65 manual Cylinder Balance Test, Conclusion No cylinder is weakest of the two cylinders
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65, 75, 55 specifications

Generac Power Systems has established itself as a leader in power generation, offering a range of high-performance generators suited for residential and commercial applications. Among its lineup, the Generac 55, 65, and 75 kW generators stand out for their reliability, efficiency, and advanced features.

The Generac 55 kW generator is designed to provide a powerful backup solution for medium to large homes or small businesses. It features a robust engine that delivers dependable performance while maintaining fuel efficiency. One of its key characteristics is the True Power Technology, which produces clean and stable power, ensuring that sensitive electronic devices run smoothly without risk of damage. This generator is equipped with a fully automatic transfer switch, allowing for seamless power transition during outages, with minimal disruption.

Moving to the 65 kW model, it offers increased capacity while retaining the fundamental qualities of the 55 kW version. This unit is particularly suited for larger homes or commercial applications that require greater power demands. The 65 kW generator utilizes Generac’s G-Force engine, known for its durability and reduced maintenance needs. Advanced features such as remote monitoring capabilities allow users to check the generator's status from anywhere, providing peace of mind and convenience.

The 75 kW generator takes performance to the next level, making it ideal for even more significant power needs. It is engineered for both quiet operation and enhanced performance, accommodating a wide range of requirements from residential to larger commercial operations. The 75 kW model includes a full-load voltage regulation system that maintains stable power output under varying loads, safeguarding appliances and equipment.

All three models incorporate advanced air-cooled technology, which enhances their efficiency and operational lifespan. Additionally, their corrosion-resistant enclosures ensure durability even in harsh weather conditions, making them suitable for diverse environments. The intuitive LCD display on each unit provides critical information, including runtime hours and maintenance reminders, empowering users with easy access to the generator's performance data.

Overall, Generac Power Systems' 55, 65, and 75 kW generators represent a commitment to quality, reliability, and innovation in backup power solutions. They are designed to meet the demands of modern power consumption while ensuring peace of mind through robust engineering and advanced technology. Whether for home use or commercial applications, these generators provide an effective means to stay prepared for unexpected power outages.
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