Pale_Horse_Idaho
Active member
- Joined
- Mar 13, 2024
- Messages
- 36
- Reaction score
- 29
- LOCATION
- Northern Idaho
I have a 14ft mirrocraft, 25hp F25 Yamaha 4 stroke 5-6krpm range (new) and here is my issue.
9 7/8 x 11 1/4 works fine with me or me and the dog. I get 5800-5900rpm. (29-30 mph) Add wife and it drops to 5450rpm.
9 7/8 x 10.5 with me + dog + wife it goes right into the rev limiter (6150rpm) 2 seconds after getting on plane. (26mph)
So there is no 9 7/8 x 10.75 but there is a stainless 9 7/8 x 11 and an aluminum 9 7/8 x 11. Would dropping 1/4 pitch bring my rpms up from 5450 into the 5800 range?
Could I go from 9 7/8 diameter to 9 1/2 for less drag? Or maybe the 11 pitch stainless would be more efficient and turn more rpms?
What I need is an 10 7/8 pitch prop.
Who would have though dropping 3/4 pitch would make such a crazy jump. Im running 90-100 % throttle with 11 1/4 but only half throttle with 10.5 to stay off rev limiter.
9 7/8 x 11 1/4 works fine with me or me and the dog. I get 5800-5900rpm. (29-30 mph) Add wife and it drops to 5450rpm.
9 7/8 x 10.5 with me + dog + wife it goes right into the rev limiter (6150rpm) 2 seconds after getting on plane. (26mph)
So there is no 9 7/8 x 10.75 but there is a stainless 9 7/8 x 11 and an aluminum 9 7/8 x 11. Would dropping 1/4 pitch bring my rpms up from 5450 into the 5800 range?
Could I go from 9 7/8 diameter to 9 1/2 for less drag? Or maybe the 11 pitch stainless would be more efficient and turn more rpms?
What I need is an 10 7/8 pitch prop.
Who would have though dropping 3/4 pitch would make such a crazy jump. Im running 90-100 % throttle with 11 1/4 but only half throttle with 10.5 to stay off rev limiter.