Jobu Saw at Glenbranter from about 1955

Date Added: 28 April 2017 Contributor: Norman Davidson Year of Photo: 2017 Picture No: 3672

The saw is courtesy of Ian Adams of Glenbranter Forest Office who has collected a considerable amount of old forestry tools.

The saw featured is a Jobu which was manufactured as Patent No 81808 and the Serial Number could be A17918 but the last figure is indistinct. The carburettor and the fuel tank are on a pivoting handle mechanism which enabled them to be maintained in an upright position whether in the felling or cross cutting mode.

The attached PDF shows the Serial Number in close up.

Any details of when this saw was manufactured and information on it would be very welcome. Note the saddle chain on the saw blade.

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Groups: Tools, equipment and clothing

1 Comment

MANUFACTURED BY:
JO-BU A/S MEKANISKE VERKSTED
DROBAK, NORWAY
SERIES OR ASSEMBLY NUMBER:

YEAR INTRODUCED:
1952
YEAR DISCONTINUED:

ENGINE DISPLACEMENT:
76ccm (4.63 cu. in.)
NUMBER OF CYLINDERS:
1
CYLINDER BORE:

PISTON STROKE:

CYLINDER TYPE:
Chrome plated aluminum on later type
early type had removable cast liner
INTAKE METHOD:
Piston ported
MANUFACTURER ADVERTISED H.P.:
2
WEIGHT:
10.4 kg with 45cm bar
(23 lbs. with 18 in. bar)
OPERATOR CONFIGURATION:
One Man operation
HANDLEBAR SYSTEM:

CHAIN BRAKE:

CLUTCH:
Manual plate clutch with cork friction pieces
DRIVE TYPE:
Roller chain reduction
CONSTRUCTION:
Sand cast aluminum
MAGNETO TYPE:
Wico
CARBURETOR:
JO-BU float type
MAJOR REPAIR KIT:

MINOR REPAIR KIT:

AIR FILTER SYSTEM:
Brass wire screen
STARTER TYPE:
JO-BU automatic rewind
OIL PUMP:
Manual
MAXIMUM ENGINE RPM:
4000
IDLE RPM:

IGNITION TIMING:

BREAKER POINT SETTING:
.015 in.
FLYWHEEL/COIL AIR GAP:

SPARK PLUG TYPE:

SPARK PLUG GAP:
.015 in.
CRANKSHAFT MAIN BEARINGS:
Ball
FUEL TANK CAPACITY:

FUEL OIL RATIO:
10-1
RECOMMENDED FUEL OCTANE:
Regular
MIX OIL SPECIFICATION:
SAE 10 in cold weather, SAE 20 or 30 in warm wather
CHAIN PITCH:

CHAIN TYPE:
JO-BU standard (scratcher) or JO-BU chipper
BAR MOUNT PATTERN:

SHORTEST GUIDE BAR SUPPLIED:
18 in. (45cm)
LONGEST GUIDE BAR SUPPLIED:
18 in. (45cm)
COLOUR SCHEME:

PAINT CODES:

ILLUSTRATED PARTS LIST:

SERVICE MANUAL:
Comment left on 31 August 2017 at 01:16 by Dave Barnes

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