20
21
ENGLISH
ENGLISH
13- SERVICING TABLE
Every use
Check the bolts and screws tightening
Check the coolant level
Check the silent-block conditions
After the first 10 hours
Replace the gear oil
Check the carburation
Every 50 hours
Replace spark pl
Clean the air filter
Replace the gear oil
Check the starter wearing and eventually replace the rope and the lockpins
Every year or every 100 hours
Replace the air filter
Replace the starter rope and the lockpins
Clean the carburetor
Replace the gaskets and the carburetor seal needle.
Change the coolant
Replace the silent-block
Replace the fuel system pipes
Every 100 hours
replace muffler springs
Check the reed valve
Check the piston, the piston rings and the small end bearing
Decarbonize and clean the decompression hole
Every 150 hours
Remove the gear and check the clutch and bell wear
Replace the piston, the piston rings and the small end bearing
replace the silencer deadening material
Replace the reed valve
Every 300 hours
Replace all the bearings and seals
Replace the crankshaft
Replace the cylinder
Every 300 hours
Replace all the bearings and seals
Replace the crankshaft
Replace the cylinder
TIGHTENING TORQUE VALUE FOR ENGINE BOLTS AND SCREWS
M
N.m
Kgf.m
Lbf.ft
Locking compound
HEAD SCREWS
6
12
1,2
8,8
HEAD NUTS
8
18
1,8
13,2
CLUTCH NUT
20
100
10
74
CRANKSHAFT NUT (IGNITION SIDE)
12
80
8
5
9
PROPELLER CENTRAL NUT (LEFT THREAD)
10
80
8
5
9
SPARK PLUG
20
2
14,8
CRANKCASE SCREWS
6
8
0,8
5,9
COUNTERSHAFT NUT
12
60
6
44,2
INTAKE MANIFOLD LOCKING SCREWS
6
8
0,8
5,9
MUFFLER STUDS NUTS
8
18
1,8
13,2
LOCTITE 270
SILENCER LOCKING SCREWS
8
15
1,5
11,1
LOCTITE 243
MUFFLER LOCKING SCREWS
8
15
1,5
11,1
LOCTITE 243
STANDARD TIGHTENING TORQUE VALUE
N.m
Kgf.m
Lbf.ft
5MM BOLT AND NUT
6
0,6
4,44
6MM BOLT AND NUT
10
1
7,40
8MM BOLT AND NUT
25
2,5
18,50
10MM BOLT AND NUT
45
4,5
33,30
12MM BOLT AND NUT
55
5,5
40,70
DATA SHEET
THOR 303
THOR 303 DS
Polini Engine
2 stroke monocylinder
2 stroke monocylinder
Cooling
Liquid cooled
Liquid cooled
Bore for stroke
76 x 62
76 x 62
Displacement
281 cm3
281 cm3
Power
38 HP at 8000 rpm
38 HP at 8000 rpm
*Max trust
120 Kg with Ø 160 cm propeller
120 Kg with Ø 160 cm propeller
R.P.M. max
8.400
8.400
Cylinder
Aluminum with Gilnisil coating
Aluminum with Gilnisil coating
Compression ratio
11,2:1
11,2:1
Piston
Two trapezoidal chromium plated rings
Two trapezoidal chromium plated rings
Intake
Reed valve in the crankcase
Reed valve in the crankcase
Carburetor
Dell’Orto VHST 28mm
Dell’Orto VHST 28mm
Air filter
Air box
Air box
Ignition 1
Electronic CDI with adj. advance
Electronic CDI with adj. advance
Ignition 2
-
Electronic CDI with adj. advance
Battery charger prearrangement
Output power 40W at 5500 RPM
Output power 40 W at 5000 RPM
Spark plug hood
5k Ω resistance
5k Ω resistance
**Fuel type
E5 petrol or LL AV GAS-al with 2,5% synthetic oil 100%
E5 unleaded petrol or LL AV GAS-al with 2,5% synthetic oil 100%
*Consumption
3 Lh 30 Kg a of static trust
3 Lh 30 Kg a of static trust
Gear reduction unit
Helicoidal teeth in oil bath with 2,8 or 3,2 reduction ratio
Helicoidal teeth in oil bath with 2,8 or 3,2 reduction ratio
Starter
Flash Starter - (Electric starter -optional)
Electric flash starter
Clutch
Centrifugal in oil bath
Centrifugal in oil bath
Muffler
Expansion with aluminum silencer
Expansion with aluminum silencer
Engine weight
Starting from Kg 20,5 (manual starter model +radiator)
Starting from Kg 22,5 wiht radiator
Propeller rotation
Clockwise
Clockwise
12- DEFECTS DIAGNOSIS
CAUSE
SOLUTION
The engine doesn't start
Out of petrol
Add petrol
Petrol doesn't reach the carburetor Check the fuel system circuit
Old or wrong petrol
Empty the tank and the fuel system circuit and replace the petrol.
Flooded engine
Remove the spark plug, start the engine, dry or replace the spark plug.
Defective spark plug
Replace it
Blackened or wet spark plug
Clean and dry the spark plug or replace it
Earth switching off cable
Check the tightening
Spark plug hood wrong installed
Check it
Carburetor has problems
Clean and check it; eventually replace the diaphragm
No spark
Check the ignition, coil and wiring
The engine doesn't idle
Dirty carburetor
Clean and check the carburetor
Out-of-adjustment screws
Calibrate the carburetor again
Defective spark plug
Replace it
The engine doesn't reach the maximum rpm Wrong carburetion
Calibrate the carburetor
The carburetor has problems
Clean and check it; eventually replace the diaphragm
The reed valve has problems
Replace the reeds or the whole reed valve
Dirty air filter
Clean or replace it
Dirty exhaust
Clean or replace the deadening material
Engine revs up when idling
Out-of-adjustment screws
Calibrate the carburetor
Air through the gaskets
Replace the gaskets and seals
*The values have been detected on the sea level at standard atmosphere. The trust and consumption values may vary according to the air temperature and density.
**E5 means the petrol type that can be used. E5= unleaded petrol 95 octanes up to 5% of ethanol. This symbol is shown on all the petrol pumps in Europe.
Only use Polini Motori original spare parte “For all the technical details/manuals/optional please check www.polini.com-> Thor section”
“The manufacturer has the right to make any modifications that can be useful to improve the features and performance of the products”
