ok i put this here becuse i still learing but here it goes. i have a power systems a 40 the one that comes with the alpha 40. what i the difference the 40 is really a 45 this the info on the two

this is the 46

Product Specifications
Type:2 stroke glow
Displacement:.47 cu in (7.65 cc)
Bore:.86 in
Stroke:.80 in
Cylinders:single
total Weight:16.96 oz
Engine (Only) Weight:13.76 oz
Muffler Weight:3.20 oz
Crankshaft Threads:1/4 x 28
Benchmark Prop:11x6 @ 12,500 rpm
RPM Range:2000-12,500
Fuel:10% - 30% Nitro
Mounting Dimensions:44mm x 17.5 mm
Muffler Type:Cast
Cylinder Type:ABC
Carb Type:Barrel, with two needles
Crank Type:Ball Bearing

this is the power systems a
Product Specifications
Type:2-stroke

Displacement:.45 cu in
Bore:.87 in
Stroke:.77 in
Cylinders:Single
Total Weight:19.52 oz
Engine (Only) Weight:16.32 oz
Muffler Weight:3.20 oz
Crankshaft Threads:1/4 x 28
Benchmark Prop:10x4
RPM Range:2,000-16,000 rpm
Fuel:10% - 30% Nitro
Mounting Dimensions:44mm x 17.5mm
Muffler Type:Cast
Cylinder Type:ABC


the bore is bigger rpm is higher the the trainer sys