ENGINE - Excelsior Special Racing. Model G.R.11, Bore 67 m m, Stroke 70.65 m m = 248.6 c.c. Model G.R.12, Bore 75 m m. Stroke 79 m m = 349 c.c. Overhead Camshaft. Vertical Shaft Bevel Gear driven. Entire mechanism totally enclosed. Alloy Bronze Cylinder Head. Down-draught Inlet. Large diameter Valves - special material. Valve Springs - Triple (Terry " AERO " quality). Camshaft on two Roller and one Ball journal. Cams on Taper and detachable. Rockers in K.E. steel on hardened Spindles and Needle Rollers. Vertical Shaft on self-aligning Ball Journals. Hardened Iron Cylinder Barrel, ground and lapped bore. R R alloy heat-treated Con-rod. Big End Sleeve shrunk in and ground in position. R R alloy heat- treated Slipper Piston. Hollow 23/32" diameter Gudgeon pin, 250 c.c., 7/8" diameter on 350 c.c., fully floating in Piston. High tensile Flywheels forged with integral large diameter Mainshafts. Whole assembly machined, ground and balanced dynamically and statically. Drive Side Main Bearing - Hoffman Special Double Row Roller. Dural Cage. Timing Side Main Bearing - Double Ball Journal. Gear Drive to Oil Pump and Magneto, incorporating built-in and positively lubricated Revolution Counter Gear Box.
EXHAUST SYSTEM - Open pipe of correct length and bore to give maximum efficiency. Chrome-plated. No silencer.
LUBRICATION - High level double gear Oil Pump. Large diameter flexible feed and filter to Pump. A" diameter Flexible Pipe carries surplus oil externally direct to the Timing Case and Sump where, with surplus oil from Big End, Cylinder and Piston it collects in Sump at a level below Flywheels (preventing oil drag). Suction Pump picks up oil and returns it to tank at a point visible at Filler Cap.
OIL CIRCULATION - 17 gallons per hour at 7,000 r.p.m.
CRADLE FRAME - " A " quality steel tubes throughout. Single top tube 1 1/2" diameter. Large webbed Steering Head. 1 3/8" diameter Front Tube.
GEAR BOX - " Excelsior " Albion 4-speed T.T. Ball Bearing Gear Box, pivot mounted. K.E. Gears and Shafts. "Excelsior" exclusive positive operation, short travel Foot Change by Heel and Toe pedal. No Kick-start.
FORKS - Genuine T.T. Forks. Central compression spring rubber mounted. Single sided, adjustable, Shock absorber. Built-in Steering Damper.
REVOLUTION COUNTER - Fitted as standard to all Racing " MANXMAN " Models. Constructed with built-in gear drive to engine, positively lubricated, and graduated to 8.000 r.p.m.
IGNITION - Lucas laboratory tested Racing Magneto.
CARBURETTER - T.T. "AMAL" Needle Type. Large single float chamber independently mounted. Feed by twin armoured flexible pipes.
TRANSMISSION - Primary Chain. 1/2" x .305". Steel chrome- plated Chain-guard. Positive adjustable Oil Feed. Rear Chain : 250 c.c., 1/2" x .305". 350 c.c., 5/8" x 1/4".
WHEELS and BRAKES - 7" diameter x 1 1/4" Brakes. Light alloy die-cast Shoes mounted on alloy anchor and side plate, with over-hung Cam Bearing. Light Steel Rims. Double butted Spokes. Front tyre : 250 c.c., 27" x 2.75", Ribbed Road Racing ; 350 c.c., 27" x 3.00", Ribbed Road Racing. Rear Tyre : 250 c.c., 26" x 3.00" Scudded Road Racing ; 350 c.c.. 26" x 3.25". Studded Road Racing. AH Racing " MANXMAN " Tyres are fitted by the Dunlop Racing Tyre Fitters.
FUEL TANK - 3 1/2 gallon steel-welded and riveted construction throughout. Completely insulated from vibration on Rubber Mountings. Large quick-action T.T. Filler Cap. Revolution Counter, well built in and Sponge Rubber Pad fitted. Finish : Black Enamel with Red side panels. (No Knee Grips).
OIL TANK - 8 pints. Quick action Filler Cap on near side. Detachable Oil Filter. Pressure Release Pipe leading to Chains.
SADDLE - DUNLOP RACING SADDLE.
MUDGUARDS - In accordance with F.I.C.M. regulations, with built-in racing number plate mounting. Fitted with T.T. Mudguard Pad.
ADJUSTABLE RACING FOOTRESTS. INDEPENDENT BRAKE PEDAL STOP. Tools and Pump included, also Spare Jets, Racing 14 mm Plug Spanner and Racing Plug.
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