PerfectPitch PROP SIZING BY MOTOR

Here is our list of recommended motor / prop combinations. Choose the largest prop that fits - bigger is better. Allow at least 10% of the diameter for tip clearance (20% is great).

In order to size your prop, you must know the gear reduction. It is stamped on a plate attached to the transmission case (between the motor and prop shaft). The same motor will require different props according to the gear reduction. To search by boat, click here.

If you notice some gaps in the chart, it's because we don't have a 14" prop yet. It is due in Spring '02. It will be available in regular and Extendo versions in 10, 11 and 12 inch pitches.

If none of our props are small enough, refer to our Extendo section. If your prop is in an aperture, see our section on Improving Apertures.

MOTOR
MODEL
HP@RPM
(Gear Ratio)
1st Choice
2nd Choice
Notes
Atomic 4  
 
 
 
 
See Universal Section
BMW D7
6@3600
(3:1)
13x10
12x11
 
Buhk DV10L
10@3000
(2.5:1)
15x11
 
 
Buhk DV10 ME
10@3000
(2.5:1)
15x11
 
 
Farymann A301
12@2500
(2:1)
15x10
 
 
Farymann K30M
6@3000
(2:1)
12x8
 
 
Farymann K34M
6@3000
(2.35:1)
13x9
12x9
 
Farymann 15W
5.9@3600
(2.05:1)
12x7
 
 
Farymann 18W
7.1@3600
(2.05:1)
12x8
 
 
Farymann 32W
10.9@3600
(2.05:1)
13x8
12x9
 
Gray Marine Seascout 91
25@2000
(1:1)
13x9
12x10
 
Palmer P60
22@3000
(2:1)
12x10
 
 
Perkins 1.18M
5@2500
(2:1)
12x10
 
 
Perkins 1.25M
8@2800
(1.85:1)
13x8
 
 
Perkins 1.36M
10@2500
(2:1)
15x10
 
 
Perkins 4108
45@3600
(1.5:1)
 
15x10
 
Perkins Perama M10
10@3600
(2:1)
 
12x8
 
Perkins Perama M20
18@3600
(2.7:1)
15x11
 
 
Perkins Perama M25
26@3600
(2:1)
15x10
 
 
Petter 12BHP
11@3000
(2:1)
13x10
 
 
Universal Atomic 1
5@3000
(2.5:1)
12x11
 
Rare
Universal Atomic 2
10@3000
(2.5:1)
15x11
 
Rare
Universal Atomic 4
30@3000
(1:1)
12x7
 
 
Universal Atomic 4
30@3000
(1:1)
13x8
12x8
For A4's w/ prop in an aperture
Universal Stevedore
18.5@3000
(1:1)
12x7
 
Canadian version of Atomic 4
Universal M-12
11@3600
(2:1)
13x8
12x9
 
Universal M3-20A
16@3600
(2:1)
 
13x10
 
Universal M4-30A
25@3600
(2:1)
15x10
 
 
Universal Model 12
10@3600
(2:1)
12x8
 
 
Universal Model 15
11@3000
(2:1)
13x10
12x11
 
Universal Model 18
14@3200
(2:1)
13x10
 
 
Universal Model 25
21@3200
(2:1)
15x10
 
 
Universal Model 25 XP
23@3200
(2:1)
15x11
 
 
Universal 5411
11@3000
(2:1)
13x10
 
 
Westerbeke W10
10@3600
(2.14:1)
13x8
12x9
 
Westerbeke W13
13.5@3000
(2.14:1)
15x9
 
 
Westerbeke W18
18@3000
(2:1)
15x10
 
 
Westerbeke W30
25@?
(1:1)
13x7
 
 
Westerbeke 12 C Two
12@3000
(2.05:1)
13x10
12x11
 
Westerbeke 20 B Two
18@3600
(2.05:1)
13x10
12x11
 
Westerbeke W 26 G
21@3000
(1.48:1)
13x9
 
 
Westerbeke W 26 G
21@3000
(1.79:1)
15x10
 
 
Westerbeke W 26 G
21@3000
(2.05:1)
15x11
 
 
Westerbeke 30 B Three
27@3600
(1.48:1)
13x9
 
 
Westerbeke 30 B Three
27@3600
(1.79:1)
13x10
 
 
Westerbeke 30 B Three
27@3600
(2.47:1)
15x10
 
 
Westerbeke 38 B Four
37@3600
(1.79:1)
15x10
 
 
Yanmar SB8
8@3200
(2:1)
 
12x8
 
Yanmar SB12
12@3000
(2:1)
13x10
12x11
 
Yanmar 2QM15
15@3000
2.14:1)
15x10
 
 
Yanmar 1GM
7.5@3600
2.62:1)
13x8
12x9
Common
Yanmar 1GM
7.5@3600
(3.22:1)
15x10
 
Rare
Yanmar 1GM10
9@3600
(2.21:1)
13x8
 
Not Common
Yanmar 1GM10
9@3600
(2.62:1)
 
13x10
Common
Yanmar 1GM10
9@3600
(3.22:1)
15x10
 
Rare
Yanmar 2GM
15@3600
(2.2:1)
 
13x10
Not Common
Yanmar 2GM
15@3600
(2.62:1)
15x10
 
Common
Yanmar 2GM20
18@3600
(2.61:1)
15x11
 
Common
Yanmar 3GM
22@3600
(2.14:1)
 
15x10
 
Yanmar 3GM30
27@3600
(2.36:1)
 
15x11
 

PerformancePropellers     Homer, NY 13077
 
Tel: (607) 749-3165, Fax: (607) 749-4604