This is the ASP-FS52AR Four-Stroke Model Airplane Engine.

Rear-Mounted Updraft Carburetor
Ball Bearing-Supported Camshaft and Crankshaft
Ringed Piston
Reversible Carburetor
Cranckase Breather: Fuel line can be attached to the nipple on the
crankcase, and Expelled Lubricants Can Then Be Directed Out Of
The Cowling.

INCLUDES: One ASP-FS52AR Four-Stroke Model Airplane Engine with: parts list, English Version of the Magnum instruction manual, muffler and header, allen wrenches, and pressure tubing.

REQUIRES: Glow plug: Four-stroke glow plug only.

SPECS: Displacement: .52 cid (8.53cc)
Bore: 23mm
Stroke: 21mm
Weight: 15.7oz
Practical rpm Range: 2,000 - 10,500
Crankshaft Thread Size: 1/4-28
Length: 3-1/8" from the Backplate to the Front of the Drive Washer.
Width: 1-1/16" Width of Engine Neglecting the Mounting Flanges
2" Including Mounting Flanges
Height: 4"
Prop: 12x5 (break-in), 11x7, 11x8, 11x9, 12x5, 12x6, 12x7, or 13x4



Fuel: Recommended by manufacturer, 10% nitromethane with 20% castor oil for break-in, no more than 15% nitromethane and no less than 16% castor oil after break-in.
Propeller: 11x8, 11x9, 11x10, 12x6, 12x7, 12x8,12x10, 13x5, 13x6 and 13x7.

SPECS: Bore: 24.8mm
Stroke: 20.6mm
Displacement: .61 cu in,
Practical rpm: 2,000-12,000
Weight: 15.5oz
Prop Nut Size: 1/14-28
Length: 91.5mm (3.60") (from backplate to front of drive washer)
Length: 120mm (4-11/16") (from backplate to front of crankshaft)
Height: 121mm (4.76") (from bottom of engine to top of head)
Width: 52mm (2-1/32") (mounting hole centers-side to side)
Width: 25mm (15/16") (mounting hole centers-front to rear)
Width: 42.6mm (1.68") (crankcase width neglecting mounting flanges)