Low speed jet L, High speed jet H GR41, GR50, RS44

MAINTENANCE

Low speed jet L

Try to ﬁnd the highest idling speed, turning the low speed needle L clockwise respectively counter-clockwise. When the highest speed has been found, turn the low speed needle L 1/ 4 turn counter-clockwise.

+ 1/4

Fine adjustment of the idle speed T

Adjust the idle speed using the idle adjustment screw T, if it is necessary to readjust. First turn the idle adjustment screw T clockwise until the cutting attachment starts to rotate. Then turn the screw anticlockwise until the cutting attachment stops. The idle speed is correctly adjusted when the engine will run smoothly in every position.The idle speed should also be well below the speed at which the cutting attachment starts to rotate.

WARNING! If the idle speed cannot be

!adjusted so that the cutting attachment stops, contact your dealer/service workshop. Do not use the machine until it has been correctly adjusted or repaired.

High speed jet H (GR41, GR50, RS44)

The high speed jet H affects the engine power, speed, temperature and fuel consumption. If the high speed jet H is set too lean (screwed in too far) the engine speed will be too high and cause engine damage. Do not let the engine run at full speed for more than 10 seconds.

Apply full throttle and turn the high speed jet H very slowly clockwise until the engine slows down. Then turn the high speed jet H very slowly anticlockwise until the engine starts to run unevenly. Now turn the high speed jet H slowly clockwise a little way until the engine runs smoothly.

Note that the engine should not be under load when you adjust the high speed jet H. You should therefore remove the cutting attachment, nut, support ﬂange and drive disc before adjusting the high speed jet H.

The high speed jet H is adjusted correctly when the machine burbles a little. If the machine races then the setting is too lean. If the engine produces a lot of smoke and burbles a lot then the setting is too rich.

CAUTION! For optimum adjustment of the carburettor, contact a qualiﬁed dealer/service workshop that has a revolution counter at their disposal.

High speed jet H (RS52)

Setting procedure without a load (Blade can be used)

The machine is equipped with speed control in the ignition system. It is extremely important to be aware of this when adjusting the carburettor.

RS52: Speed control at: 13500 rpm

When attempting to adjust the speed over that speciﬁed, the speed is not changed, but only causes the engine to receive too little fuel resulting in a large risk of engine failure.

Run the machine warm for approximately 5 minutes alternating between short intervals of full throttle and idling. When the carburettor is to be adjusted, apply full throttle and turn the H-needle anti-clockwise until the engine speed reaches 10,500-11,000 r/min (burbles) or until the cap reaches its stop position. Now turn the H-needle slowly clockwise until the engine reaches the speed when the speed control comes into force. In some cases, speed control can come into force at 200-300 revs below or above that speciﬁed. It is important that you do not continue to turn the H-needle clockwise when the engine speed has stabilised. Screw the H-needle (anti-clockwise) a few tenths of a turn instead.

Setting procedure with a load (Trimmer head should be used)

Ensure the length of the trimmer cord is correct, i.e. exactly reaches the knife on the trimmer guard. Use either 3 mm or 3.3 mm diameter trimmer cord.

Run the machine warm for about 5 minutes mostly at full throttle. When the carburettor is to be adjusted, apply full throttle and turn the H-needle anti-clockwise until the engine burbles or until the cap reaches its stop position. (If the engine runs smoothly when the cap is in its stop position no further adjustment is necessary!) Turn the H-needle slowly clockwise until the engine runs absolutely smoothly. (Burbling has stopped completely). Now screw the H-needle (anti- clockwise) a few tenths of a turn.

CAUTION! For optimum adjustment of the carburettor, contact a qualiﬁed dealer/service workshop that has a revolution counter at their disposal.

26 – English

GR50 specifications

The Jonsered GR50 is a robust and versatile garden tractor that caters to the needs of both residential and professional gardeners. Designed for performance, the GR50 merges comfort and advanced technology, making it a popular choice among gardening enthusiasts.

One of the standout features of the Jonsered GR50 is its powerful engine. It comes equipped with a high-performance overhead valve engine that provides excellent torque and reliability. This engine ensures that the tractor can handle various terrain types and grass heights, making it ideal for both small and large lawns. Additionally, the high-efficiency engine minimizes fuel consumption while maximizing power output, making it an economical choice for users.

The GR50 offers an impressive cutting deck, which is available in various sizes to meet different mowing needs. The adjustable cutting height allows users to customize the grass length, ensuring a clean and even cut every time. The cutting deck design incorporates anti-scalp wheels, which help to prevent turf damage, especially on uneven surfaces. This feature is crucial for maintaining a healthy lawn and enhancing the overall appearance of outdoor spaces.

One of the key technologies integrated into the Jonsered GR50 is its hydrostatic transmission, which provides smooth and uninterrupted speed control. Users can easily adjust their mowing speed without constantly shifting gears, making it easier to navigate around obstacles or maneuver in tighter spaces. This feature significantly improves user experience and efficiency during mowing tasks.

Comfort is also a top priority in the design of the GR50. It features an ergonomically designed seat that is both adjustable and padded, allowing users to mow for extended periods without discomfort. The easy-to-use dashboard includes intuitive controls that enable quick adjustments and settings changes. This focus on user comfort and convenience makes the GR50 a delight to operate.

Furthermore, the Jonsered GR50 is designed with durability in mind. Its robust construction, combined with high-quality materials, ensures that it can withstand the rigors of regular use. This makes it a reliable investment for anyone looking to maintain their garden or lawn.

In summary, the Jonsered GR50 is a powerful, efficient, and comfortable garden tractor that embodies the perfect blend of technology and user-friendly features. With its strong engine, versatile cutting deck, hydrostatic transmission, and ergonomic design, it stands out as a top choice for gardening tasks. Whether for residential use or professional landscaping, the GR50 delivers exceptional performance and reliability.

Jonsered GR50 manual Low speed jet L, Fine adjustment of the idle speed T, High speed jet H RS52

Models: GR50