17 OUTRAGE II Yamaha I-4 V MAX SHO® 115
Posted: Mon Dec 21, 2020 1:55 pm
I have a 1998 17 Outrage II with a new Yamaha [that was later clarified to be an I-4 V MAX SHO 115]; it replaced a 1998 Yamaha 130-HP two-stroke-power-cycle engine. I chose the [Yamaha I-4 V MAX SHO 115] due to [concern about too much] transom weight. I wanted to stay within specification. Boston Whaler [gave a recommendation in some communication that] 420-lbs was the maximum [engine] weight.
[The Yamaha I-4 V MAX SHO 115 was later clarified to have a weight of 377-lbs.] [The weight of the old engine was not given but was later clarified to be 368-lbs.] [The] gear ratio [of an unidentified engine which was lated independently verified to be the new engine] is 2.15:1. The boat weight is 1700-lbs.
The [propeller under test] is a Solas TITAN stainless steel three bladed 13-1/4 x 17-pitch, used previously with the old engine.
PERFORMANCE DATA
Old Engine
The old 130-HP accelerated to 5,800-RPM and the boat speed was 41-MPH [with the propeller under test].
New Engine
The new F115 SHO accelerates to 6,000-RPM, and the boat speed is 37-MPH [with the propeller under test]. The new engine gets [the boat] on plane, but [the boat] just feels sluggish.
[One question posed four test conditions; the question has been rewritten into four separate questions--Moderator]
Q1: what would be the top boat speed if the propeller pitch were increased?
Q2: what would be the top boat speed if the propeller pitch were decreased?
Q3: how would acceleration from a standing start onto plane be affected if the propeller pitch were increased?
Q4: how would acceleration from a standing start onto plane be affected if the propeller pitch were decreased?
[The Yamaha I-4 V MAX SHO 115 was later clarified to have a weight of 377-lbs.] [The weight of the old engine was not given but was later clarified to be 368-lbs.] [The] gear ratio [of an unidentified engine which was lated independently verified to be the new engine] is 2.15:1. The boat weight is 1700-lbs.
The [propeller under test] is a Solas TITAN stainless steel three bladed 13-1/4 x 17-pitch, used previously with the old engine.
PERFORMANCE DATA
Old Engine
The old 130-HP accelerated to 5,800-RPM and the boat speed was 41-MPH [with the propeller under test].
New Engine
The new F115 SHO accelerates to 6,000-RPM, and the boat speed is 37-MPH [with the propeller under test]. The new engine gets [the boat] on plane, but [the boat] just feels sluggish.
[One question posed four test conditions; the question has been rewritten into four separate questions--Moderator]
Q1: what would be the top boat speed if the propeller pitch were increased?
Q2: what would be the top boat speed if the propeller pitch were decreased?
Q3: how would acceleration from a standing start onto plane be affected if the propeller pitch were increased?
Q4: how would acceleration from a standing start onto plane be affected if the propeller pitch were decreased?