Hello,
We recently purchased a -new to us- 2015 S20 in mint condition. Yamaha F70 (145 hrs) A real find. Anyway, we took it out the first time and had 5 adults and one medium dog on board. We have had many larger boats over the past 40 years but this is the first pontoon. I am getting too old to keep up with larger boats anymore. So I knew this pontoon was going to be slow, that wasn't my concern. All but 1 adult ended up on the rear couch (and the dog) and one sat up front in front of me at the helm. Once we got going I noticed that it looked like Moses parting the Red sea behind us and at WOT we were at 18-19 mph (which is fine, I knew that would be the speed when I bought it) But at WOT it was only getting around 4500 rpms. Specs say this engine should be between 5300-6300 at WOT, so maybe I am too low in the water. I don't want to bog the engine so I need to know who can tell me which mounting hole for the engine. A Bennington rep says he feels the engine was mounted properly due to getting that much speed with that load. All I can find online so far is some say 4" below the waterline for cavitation plate at rest. Mine siting here in my driveway is about 8" below the waterline.
The speed is ok for us, we are older and just cruising the ICW near our house. My main concern was why the rpms wouldn't reach in the WOT range for this motor.
It looks like the mounting hole was at one time in the #2 position (now in top hole #1 which lowers it all the way down) and the prop has been changed to a 14Dx12K SS. It may have had Benningtons recommended prop on it to begin with. So I will re-arrange the load for more weight up front and see what it does. It is in the #1 mounting hole now and the bottom V of the transom is about 1-1/2" above the cav plate. Maybe I just need to reprop to the Yamaha alum. prop that Bennington recommends. Any advice is greatly appreciated.
We recently purchased a -new to us- 2015 S20 in mint condition. Yamaha F70 (145 hrs) A real find. Anyway, we took it out the first time and had 5 adults and one medium dog on board. We have had many larger boats over the past 40 years but this is the first pontoon. I am getting too old to keep up with larger boats anymore. So I knew this pontoon was going to be slow, that wasn't my concern. All but 1 adult ended up on the rear couch (and the dog) and one sat up front in front of me at the helm. Once we got going I noticed that it looked like Moses parting the Red sea behind us and at WOT we were at 18-19 mph (which is fine, I knew that would be the speed when I bought it) But at WOT it was only getting around 4500 rpms. Specs say this engine should be between 5300-6300 at WOT, so maybe I am too low in the water. I don't want to bog the engine so I need to know who can tell me which mounting hole for the engine. A Bennington rep says he feels the engine was mounted properly due to getting that much speed with that load. All I can find online so far is some say 4" below the waterline for cavitation plate at rest. Mine siting here in my driveway is about 8" below the waterline.
The speed is ok for us, we are older and just cruising the ICW near our house. My main concern was why the rpms wouldn't reach in the WOT range for this motor.
It looks like the mounting hole was at one time in the #2 position (now in top hole #1 which lowers it all the way down) and the prop has been changed to a 14Dx12K SS. It may have had Benningtons recommended prop on it to begin with. So I will re-arrange the load for more weight up front and see what it does. It is in the #1 mounting hole now and the bottom V of the transom is about 1-1/2" above the cav plate. Maybe I just need to reprop to the Yamaha alum. prop that Bennington recommends. Any advice is greatly appreciated.
