Table of Contents
This is an old revision of the document!
REF: Extra Models11
XR-750 Engine Mechanicals – Top & Bottom End
1972 Specs / Features
New redeigned 750cc engine with aluminum cylinders and heads. Also had new valves, pistons, rods, flywheel assm, “E” cams, carbs and tuned exhaust, 7/8“ dia handlebars with an aluminum ball end clutch lever and a fiberglass seat/fender with with a foam cushion.
- Engine Type: OHV V-Twin
- Carburetion: Dual 36mm Mikuni carburetors and specially designed air filters
- Exhaust System: Tuned duals with reverse-cone megaphones
- Bore and Stroke: 3.125” x 2.983“
- Displacement: 45cu, 750cc
- Compression Ratio: 10:1
- Max RPM: 8000
- Clutch Type: Multi-plate dry clutch
- Primary Drive: 25 tooth engine sprocket, 59 tooth clutch, triple row roller chain
- Rear Drive: 16 tooth transmission sprocket, 40 tooth rear wheel sprocket
- Overall Drive Ratio: 5.90:1
- Transmission: Constant Mesh, 4 speed
- Transmission Gear Ratios:
- 1st 2.09:1
- 2nd 1.51:1
- 3rd 1.14:1
- 4th 1:1
- Weight: 295 lbs
- Tires (front and rear): 4.0 x 19 on aluminum rims
- Front Forks: Ceriani with 4.40” travel and aluminum fork bracket
- Rear Shocks: Girling hydraulic racing shocks
- Gas Tank: Fiberglass construction with 2-1/2 gallon capacity
- Oil Tank: 3 quarts
- Electrical: Fairbanks-Morse magneto
- Color: Jet Fire Orange