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Excelsior 250cc G11 Manxman OHC & G12 350cc


THE 250 c.c. " MANXMAN " MODEL G.ll.

ENGINE - Excelsior Overhead Camshaft Engine of advanced design, built throughout to give highest possible efficiency and maximum power output incorporating many components of the Winner of 1933 Lightweight T.T. at Record Speed. All internal parts are specially strong and massive ; Bore & Stroke, 249 c.c. - 67 m/m. x 70.65 m/m ; 349 c.c. - 75 m/m. x 79 m/m.

Crank shaft mounted on double row Special Hoffman roller bearings on drive side and ball bearings on timing side.

Crank pin of 1.4" diameter has double row caged roller bearings.

Flywheels which are integral with the main shafts of 1 1/8" diameter are made from high tensile steel forging. Con-rod is of special alloy of immense strength.

Piston is three-ring slipper type, hollow gudgeon pin 23/32" diameter on 250 c.c. and 7/8" diameter on 350 c.c.

Camshaft drive is arranged with bevels of case hardened steel gears, the hunting tooth principle being incorporated to eliminate excessive wear of gear wheels.

Vertical shaft is 3/4" diameter mounted on four bearings with specially ground Oldham Couplings at top and bottom.

CAMSHAFT runs on THREE BEARINGS, the cams being fitted on a taper and easily removable.

ROCKER SHAFTS are mounted in substantial bronze bushes in camshaft housing.

ROCKER BEARINGS are long bronze bushes and hardened steel cam follower rollers.
Exhaust and inlet VALVE GUIDES are bronze in both cases.

LUBRICATION - Dry sump lubrication carried out by two gear pumps which arc kept primed under all conditions. The feed pump forces oil to the big end and cylinder head cam- shaft assembly. The head is completely drained on stopping the engine and all surplus oil passes down the vertical shaft tunnel to the enlarged double sump in the special alloy crank case.

FRAME - Entirely new type cradle frame constructed of large diameter tubes of exceptional strength ensuring perfect steering and absolute rigidity at high speeds. Sidecar lugs integral with frame.

FORKS - Genuine T.T. type forks with taper tubes and large steering damper and shock absorbers.

GEARBOX - Heavyweight Four-Speed, with enclose* positive change Foot Control and cork clutch running in oil Foot change lever mounted on splined shaft, adjustable for position.

TANK - Large Welded steel saddle tank, chromium plated with red side panels (black enamel tank optional). Mounted or rubber with complete insulation from frame. Capacity 3] gallons Oil tank mounted on seat down cube. Capacity eight pints Both tanks fitted with quick action hinged filler caps.

CARBURETTER - Large bore " AMAL," with downswept intake operated by quick action twist grip.

WHEELS and TYRES - Built up with 7" forged steel hub and high tensile steel axles, with journal Bearings to rear wheel DUNLOP CORD Tyres, 27" x 3" ribbed front, and 26" x 3.25' studded rear.

BRAKES - Internal expanding with Finger adjustment, 7' diameter front and rear with forged steel drums and 1 3/4" wide special alloy shoes.

TRANSMISSION - Totally enclosed front 1/2" x .305" chain in Cast Aluminium Oilbath case.
Rear chain - 1/2" x .305" on 250 c.c. and 5/8" x 1/4" on 350 c.c., with top half chain cover and positively lubricated.

MUDGUARDS - Strong ribbed section steel guards with hinged rear to-facilitate wheel removal.

HANDLEBARS - Adjustable with Forged Steel external lever; and separate adjustments.

IGNITION and LIGHTING - Miller 6 Volt Dyno-Mag (combined dynamo and magneto with detachable dynamo portion) equipped with quickly detachable 8" headlamp and instrument panel in tank.

SILENCER - Downswept pipe with megaphone type silencer giving adequate silence and having instantly detachable baffles (Upswept pipe optional). TOOLBOX and

EQUIPMENT - Shaped metal toolbox with separate compartment concealing accumulator. Full set of tools. Electric horn. Licence holder. Prop stand.

WEIGHT - In Touring trim with lighting set : 250 c.c. 325 lbs. 350 c.c. 335 lbs. Approx.

250 c.c. Model G.11

Code Word : "MANXAN"


350 c.c. Model G.12

Code Word : "MANXOT"



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