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Owner's Manual for Cobra Fortis 14L, 17B, 20B, 25B Lawn Mower
Quick guide for the Cobra Fortis series lawn mowers. Includes assembly, starting procedures for Loncin and Briggs & Stratton engines, cutting height adjustment, cartridge replacement, and maintenance tips.
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This manual provides essential operating and maintenance instructions for the Cobra Fortis series (14L, 17B, 20B, 25B). Always read the full manual before use. The mower is designed for home gardening and fine turf sports fields. Warning: Do not use on slopes exceeding 22 degrees. Never operate without the grass catcher or discharge guard in place.
Parts description
Key components include the throttle lever, upper/lower handles, drive and cylinder clutch levers, fuel cap, grass box collector, front roller, cutting cylinder, and height of cut control.
Assembly
Align the upper handle with the lower handle. Insert the quick-release lever with a washer on both the inside and outside of the handlebar, then secure with the nut and tighten using a 13mm spanner. Repeat for the other side.
Preparing for use
The mower is shipped without oil. Fill the crankcase with SAE 30 engine oil to the upper limit on the dipstick. Use unleaded fuel and refuel outdoors only. Ensure the spark plug connector is firmly attached before starting.
Operation
Starting: Set the engine switch to 'ON', move the throttle to 1/3 'FAST', set the fuel valve to 'ON', and move the choke to 'CLOSE' (for cold engines). Pull the starter grip until resistance is felt, then pull quickly. Gradually move the choke to 'OPEN' as the engine warms.
Mowing: Use the cylinder control lever to engage the cutting blades and the drive control lever to move the mower forward. Release both to stop.
Maintenance and storage
Regularly check all nuts, bolts, and screws. Clean the mower after use, but do not use a pressure washer. Lubricate the height adjuster knob and the inner shaft of the front roller. Always disconnect the spark plug wire before performing any maintenance or changing the cartridge.
Changing the cartridge
The Fortis system supports 7 different cartridges. To change: remove the side cover, unscrew the cartridge bolts, remove the belt from the pulley, and carefully lift out the cartridge. Reverse the process to install a new one.
Troubleshooting
If the grass is not cut cleanly, check the cylinder-to-bottom blade gap. If the engine fails to start, check for a flooded engine or disconnected spark plug. For excessive vibration, contact a local Cobra dealer.
Manufacturer information
Cobra Electronics
Practical help
Common problems
Grass is not cleanly cut or is ripped
Check and adjust the cylinder to bottom blade gap; sharpen the cylinder if necessary.
Engine starting problems
Engine may be flooded; wait 10-15 minutes. Check if the spark plug lead is connected.
Cutting cylinder does not rotate
Remove any obstructions and adjust the cylinder-to-bottom blade gap.
Excessive vibration or noise
Inspect the blade system and other parts for damage; contact a local Cobra dealer.
Before use
- Check oil level and fill with SAE 30 oil if necessary.
- Inspect all fixings, screws, and bolts for tightness.
- Ensure the area to be mowed is clear of debris (stones, toys, wires).
- Verify that the grass catcher or discharge guard is correctly fitted.
- Check that the spark plug connector is firmly attached.
Specs in practice
- Cutting Height
- Adjustable from 6mm to 30mm with standard 6-blade cartridge; as low as 3mm with optional 10-blade cartridge.
- Fuel Tank Capacity
- 3.6L for Fortis 14L; 1.9L for 17B; 3L for 25B.
- Grass Catcher Capacity
- Ranges from 55L (14L model) to 90L (25B model).
Images and diagrams
- Fig. 13: Oil filling and level check using the dipstick.
- Fig. 26: Operation of the cylinder and drive control levers.
- Fig. 30/31: Height of cut adjustment mechanism.
- Fig. 45: Lubrication points for the height adjuster and front roller shaft.
Model compatibility
- The Fortis system is compatible with 7 different cartridges for scarifying, dethatching, brushing, verticutting, and aerating.
Manual page author
Emily Carter
User documentation editor
Prepares concise manual descriptions and highlights the most useful setup, operation, and maintenance information for readers.