Starting propellor sizes are mid range pitch props that should fly just about any plane designed for that engine.  Try these first as in most cases they will be close to the correct size.  Then use trial and error to try and fine tune performance by trying alternate props.  The choice of propellers, wood, plastic or composite, pitch and length is very much a personal choice and in many cases depends on the type of aircraft your flying as well as your flying style.

Have a good day at he field

Engine size        Starting prop                                                 Alternate Props

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.049                    6X3                      5.25x4   5.5x4   6x3.5   7x3

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.09                      7x4                      7x3   7x4   7x5

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.15                      8x4                      8x5   8x6   9x5

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.19 - .25              9x4                       8x5  8x6   9x5

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.20 - .30              9x6                       9x5   9.5x6   10x5

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.35 - .36              10x6                     9x7   9.5x6   10x5

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.40                      10x6                    9x8   11x5

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.45 - .47              10x7                    10x6   11x5   11x6   12x4

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.50                      11x6                    10x8   11x7   12x4   12x5

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.60 - .61              11x7                    11x7.5   11x7.75   11x8   12x6

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.70                      12x6                    11x8   12x8   13x6   14x4

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.78 - .80               13x6                   12x8   14x4   14x5

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.90 - .91               14x6                   13x8   15x6   16x5

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1.08                     16x6                   15x8   81x5

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1.20                     16x8                   16x10   18x5   18x6

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1.50                     18x6                   18x8    20x6

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1.80                     18x8                   18x10   20x6   20x10   22x6

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                                                                 FOUR STROKES

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.20 - 21 FS           9x6                     9x5   10x5

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.40 FS                 11x6                   10x6   10x7   11x5   11x7   11x7.5   12x4   12x5

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.45 - .48 FS         11x6                   10x6   10x7   10x8   11x7   11x7.5   12x4   12x5   12x6

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.60 - .65 FS         12x6                   11x7.5   11x7   11x8   12x8   13x5   13x6   14x5   14x6

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.80 FS                 13x6                   12x8   13x8   14x4   14x6

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.90 FS                 14x6                   13x6   14x8   15x6   16x6

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1.20 FS               16x6                   14x8   15x6   15x8   16x8   17x6   18x5   18x6

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1.60 FS               18x6                   15x6   15x8   16x8   18x6   18x8   20x6

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2.4 FS                 18x10                 18x12  20x8   20x10

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2.7 FS                 20x8                   18x10   18x12   20x10

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3.0 FS                 20x10                  18x12

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