anonOmattie
Seaman Apprentice
- Joined
- May 26, 2017
- Messages
- 42
hello. ive got a new boat, a 4.5m speedboat, with a 25hp mercury XD longshaft on the back. im struggling to get good performace on this boat so far. on my own i get almost 28kmh, but with 2 people inside it barely reaches 20kmh. the prop it is running is a 4blade 10x12.
today i was driving on a small canal, and the following happened. i was full throttle, going 20kmh, when i was taking a slight turn. suddenly my motor dropt in rpm and picked up some speed! it was not making high waves anymore and was planning quit nice, even better than when im driving on my own. also, when slightly turning the boat wobbles a bit, only to one side (i quess the rotation of the prop?).
when with 2 people, this is almost the same situation: https://www.youtube.com/watch?v=E-IuE-Klacs&index=7&list=WL
high rpms, but not a lot of speed... when after a turn it dropped in rpms and picked up speed.
could someone help me with this situation? i thought it was an oversized prop, but now im thinking more of the outboard height...
today i was driving on a small canal, and the following happened. i was full throttle, going 20kmh, when i was taking a slight turn. suddenly my motor dropt in rpm and picked up some speed! it was not making high waves anymore and was planning quit nice, even better than when im driving on my own. also, when slightly turning the boat wobbles a bit, only to one side (i quess the rotation of the prop?).
when with 2 people, this is almost the same situation: https://www.youtube.com/watch?v=E-IuE-Klacs&index=7&list=WL
high rpms, but not a lot of speed... when after a turn it dropped in rpms and picked up speed.
could someone help me with this situation? i thought it was an oversized prop, but now im thinking more of the outboard height...