1918
GG
After having aerated heavily 
moss-covered areas, it is recommended to resow the lawn. 
This will help the affected lawn 
to recover quickly. 
The aerator cylinder use is 
optional depending on the needs 
and condition of the lawn. 
The table below provides information on the use of the aerator 
cylinder. 
6.4 Mowing with the 
grass catcher (Fig. I)
As soon as there are grass clippings left on the lawn during 
mowing and aerating, the grass 
catcher should be emptied.
To remove the grass catcher (18) 
lift the protective cover (27) on 
your petrol Hattrick lawn mower 
with one hand. With the other 
hand hold the grass catcher (18) 
by the carrying handle (17) and 
remove the grass catcher (18) 
upwards.
If the protective cover (27) is released, it automatically shuts and 
covers the discharge opening.
If grass clippings stick in the discharge opening, the mower may
be difficult to start. Pull the petrol 
Hattrick lawn mower back about 
1 m so that the grass clippings 
drop out easily. 
Afterwards, the grass catcher 
should be emptied.
Note: 
To ensure good collection, regularly clean the grass catcher 
inside and outside.
Attaching the grass catcher
A
Attach the grass catcher
only with the engine 
switched off and the cutting 
blade at a stand still.
Lift the protective cover (27) with 
one hand. With the other hand 
hold the grass catcher (18) by 
the carrying handle (17) and insert into the the discharge opening from above.
Note: 
If properly seated the protective cover (27) fits snugly to 
the grass catcher (18).
Mowing without 
the grass catcher
The protective cover (27) is 
mounted in such a way that the 
petrol Hattrick lawn mower can 
be used without the grass catcher 
with the protective cover (27) 
closed. The clippings are ejected 
onto the lawn below the protective cover (27). 
Follow the manufacturer’s 
instructions when replacing 
the blades, blade bar and for
aerator cylinder.
7.2 How to replace the blades, 
blade bar and the aerator 
cylinder (Fig. K - M)
Please use only the Original 
GARDENA Spare Blades: 
Triangular blades 
(HB 40) Art. No. 4098 
Rectangular Blades 
(MulchCut HB 40) Art. No. 4099 
Aerator cylinder  Art. No. 4097
You can order these spare parts 
from your GARDENA dealer 
or directly from the GARDENA 
customer service.
Never use spare parts or accessories which have not been 
designed by the manufacturer!
Replacing the blades (Fig. K)
Note: 
The blade has two cutting 
edges. If one edge has become 
blunt the blade can be reversed. Broken blades must be 
replaced immediately as it can 
cause an imbalance problem.
Do not regrind the blades, it 
will cause imbalance.
The blades must always be 
replaced or reversed in pairs.
When replacing the blades 
always use the new nuts and 
bolts supplied with the spare 
blades.
1. Remove the spark plug in 
order to avoid risk of injury 
if the engine is accidentally 
started.
2. Empty the tank or run 
A the mower until the
tank is empty! Make sure the 
tank lid is properly closed.
Tilt the lawn mower to the 
tank-located side; keep spark 
plugs and sound absorber of 
the motor upwards. 
3. Hold the locking nuts (28) at 
the back and unscrew the bolts 
(29), using the TORX
®
-wrench
provided. 
4. Reverse the blades (30) or 
mount new blades (30) and 
secure tightly (torque 25 Nm). 
(During installation make sure 
that the ratchet toothed locking 
washers (31) are fitted under 
the nuts (28) and that the nuts 
(28) are on the top of the blade 
bar (32).)
Replacing the blade bar
(Fig. L)
Damaged blade bars must be 
replaced to prevent imbalance.
1. Remove the spark plug in 
order to avoid risk of injury 
if the engine accidentally 
is started.
2. Empty the tank or run 
A the mower until the
tank is empty! Make sure the 
tank lid is properly closed.
Tilt the lawn mower to the 
tank-located side; keep spark 
plugs and sound absorber of 
the motor upwards. 
3. Release the hexagon head 
bolt (33) with an appropriate 
wrench (SW 13) and remove 
the blade bar (32) from the 
drive shaft.
4. Insert new blade bar and 
tightly screw with the following 
washers (in the same order): 
a) fibre washer (34) 
b) strain washer (35) 
c) small steel washer (36) 
and with the hexagon head 
bolt (33) (Torque: 40 Nm).
Be sure that strain washer (35) 
has been installed in the correct position (see fig. L1).
Replacing the aerator cylinder 
(Fig. M) 
The aerator cylinder is subject 
to natural wear and tear. If the 
springs (37) are worn it will not 
function correctly. 
The aerator cylinder (38) must 
be replaced.
1. Remove the spark plug in 
order to avoid risk of injury 
if the engine is accidentally 
started.
2. Empty the tank or run 
A the mower until the
tank is empty! Make sure the 
tank lid is properly closed.
Tilt the lawn mower to the 
tank-located side; keep spark 
plugs and sound absorber of 
the motor upwards. 
3. Release screws (39) with 
an appropriate Phillips head 
screwdriver.
4. Remove the bearing sheet 
steel (40).
5. Remove aerator cylinder (38) 
together with end plate (41) 
of the drive shaft (42) (square) 
by tilting and pulling out. 
6. Place new aerator cylinder (38) 
onto drive shaft (42) (square); 
stick on end plate (41) and 
tighten with the bearing sheet 
steel (40) in the casing.
7.3 Engine maintenance
Changing oil (Fig.E) 
Always change the oil when 
the engine is hot and the tank 
is empty and closed.
Carry out the first motor oil 
change after 5 hours of operation, 
then every 50 hours of operation 
or once a year at the end of the 
mowing season, depending on 
which comes first. 
In order to do this, open oil sealing cap (21), tilt the mower so 
that the old oil can flow into an 
oil-trough. Dispose of waste oil 
according to local regulations. 
Position the mower on a level 
surface again and fill it with motor 
oil (0.6 l SAE 30 or 10W 30) 
(see 5.1).
Checking and cleaning 
the spark plug
Clean a contaminated spark plug 
with a brass wire brush and rag. 
Check the electrode gap (setting:
0.75 mm gap). Replace a badly
worn or damaged plug. 
Cleaning the air filter (Fig. N) 
Cleaning the air filter is necessary every 3 months or after 
25 hours of operation. In extreme dusty conditions do so 
more frequently.
Remove screw (43). 
Fully remove air filter by pulling 
sideways and/ or from the front. 
Use of the aerator cylinder Cutting height setting Function of the aerator cylinder
Deep aeration of the soil 30 - 35 mm The aerator springs penetrate up to 7 mm
deep depending on the type of soil.
Aeration of the soil surface 35 - 40 mm The aerator springs remove moss, 
matting, and weeds rooting near the 
surface.
Combing the lawn 40 - 45 mm The aerator springs remove residues from 
the lawn.
Gathering grass clippings etc. 40 - 55 mm The aerator springs remove even wet or 
trodden-in grass clippings etc. from the 
lawn.
7.1 Maintenance
Maintenance includes all jobs 
which keep your petrol Hattrick 
lawn mower in perfect working 
order. By regularly checking the 
unit (firm seating of screw connections, cracks, damage) and 
replacing defective or worn parts 
you can prevent accidents and 
failure.
Repairs may only be carried 
out by GARDENA service 
centres or dealers authorised 
by GARDENA.
A
Attention: Always detach
the spark plug before 
working on your petrol Hattrick 
lawn mower (for checking and 
maintenance) to prevent risk 
of injury!
For security reasons, replace 
the tank lid if damaged.
Ne
ver clean your petrol Hattrick 
lawn mower with running water, 
in particular with water under 
high pressure.
Store your petrol Hattrick lawn 
mower in a dry place where 
it is protected from frost. The 
lawn mower should be stored 
out of the reach of children.
7. Maintenance, service, storage