Tower 46 Specs pasted from the Tower web site:

Displacement: 7.5cc (.455 cu in)
Bore: 22mm (.866")
Stoke: 19.6mm (.772")
Horsepower: 1.75 BHP at 16,000 RPM
Weight: 475g (16.9 oz) (with Muffler)
Length: 83mm (3-1/4") From Backplate to Front of Drive Washer
17.55mm (11/16") Front to Rear Mounting Hole Centers
Width: 35.4mm (1.39") Width Neglecting Engine Mounting Flanges
44mm (1.73") Side to Side Mounting Hole Centers
Height: 89mm (3-1/2")
Muffler Length: 171mm (6-3/4")(Overall)
Muffler Diameter: 40mm (1-9/16")
Crankshaft Thread Size: 1/4-28
Recommended Props: Break In: 10X7
Trainer and Sport Models: 10X6, 10x7, 10x8, 11x6
Scale Models: 10X6, 10x7, 11x6, 11x7
Operating RPM Range: 2,500 - 16,000 RPM

The blinking smiley faces are not mine. They must be the result of a formatting problem?
Enjoy,

Jim