General description of JONSEREDS 49SP
20
v
17
16
15 14
1. Anti-vibration mounts. 2. Rear handle. 3. Throttle safety catch. 4. Throttle catch for starting. 5. Stop switch. 6. Bar
mounting studs. 7. Oil strainer cap with safety chain-guard pin. 8. Clutch guard. 9. Cylinder cover. 10. Front handle.
11. Air filter cover. 12. Choke control. 13. Throttle trigger. 14. Fuel tank cap. 15. Adjusting screws for carburetor. 16.
Lubrication hole for starter spring. 17. Recoil starter. 18. Starter handle. 19. Adjusting screw for oil pump feed. 20. Guard
for right hand. 21. Chain bar. 22. Saw chain. 23. Muffler. 24. Built-in vibration damper. 25. Oil tank cap. 26. Oil pump.
27. Drillings for bucking spike. 28. Chain tension adjusting screw.
Jonsereds 49 SP is powered by a single-cylinder, air-cooled,
two-cycle engine of the loop scavenging type.
The ignition system consists of a flywheel magneto made
by Pagani. The ignition coil is separately located outside
the flywheel.
The fuel tank has a check valve to prevent pressure or
vacuum build-up in the tank.
The carburetor is an all-position Tillotson diaphragm type.
Lubrication of chain and bar is by an automatic pump
with adjustable oil feed.
The starter is made up of a recoil unit with a nylon rope
and rewind spring.
Chain pitch 3j8" or 0.325 inch.
Drive link gauge 0.058 inch (i.e. thickness 1.47 mm).
Chain speed 3540 feet per minute (18 mjsec.) at 8000 rpm
with an eight-tooth sprocket.
Engine displacement 3 cu in (49 cc).
Compression ratio 9: 1.
Bore X stroke =1.732 X 1.260 inch (44 X 32 mm).
Fuel tank capacity 1* US pints (0.8 liter).
Oil tank capacity * US pint (0.3 liter).
21
22
28 27 26
25 24
Engine
maintenance
The engine is tested and preset at the factory.
During its first 10 to 15 hours of operation the engine
should not be run continuously under maximum load. Cut-
ting should, however, always be carried out at full engine
speed.
Clean the cooling fins and air intake screen regularly or
the engine will run hot and be damaged by overheating.
Check the spark plug about every second week. The gap
between the electrodes should be 0.020 inch (0.5 mm). The
spark plug has a relative short service life in a two-cycle
engine. The manufacturers recommend spark plug replace-
ment every 75 hours of operation. Make sure you get
the right spark plug with the correct heat value, i.e. the
same type as that originally installed by the factory.
0.020 inch (0.5 mm)
Spark plug gap
Remove the fan cover and cylinder cover once a week to
. clean the cylinder fins.
To Next Page
Loading...
Need help?
General
