review of West Marine 350 with Yamaha 25 HP EFI manual start

[schoonerdog]

Yamaha this year came out with the new electric fuel injected 25HP engine. Their new engine has reduced weight from 170 lbs to around 125 lbs or so, giving it the greatest HP to weight ratio of any of their 25 HP engines (two stroke included!). It's a nice engine, and I have it now paired with a WM 350 RIB. At idling speed, the engine is very quiet, you can carry on a conversation with someone on the dock without raising your voice. At around half throttle with two kids and two adults (about 600 lbs of people weight), we can go around 12-13 knots and 18 knots wide open throttle (around 600 lbs of people weight). We can get 4 adults and three kids (800 - 900 lbs) onto a very nice riding plane.

No complaints about the RIB itself, seems to be aging well (it's now 2 years old), West Marine seems to stand behind their products. The bow locker is decent sized, but will be wet, so you need to put things in a dry bag.

[SailorSpencer]

I have the same a wm350 Dbl Bottom hypalon. It's aged well over the past 3years. I ran a mercury 15hp 2 stroke for the past few years. It would plane 3 adults barely. With two I would max at 17kts. I now have a Lehr 15hp 4 stroke and it planes 2 adults and a kid just fine. I haven't carried the GPS to catch a speed yet or carried more people onboard, but I imagine it'll perform the same as the 2 stroke did.
Our bow locker gets wet too, we carry a small hand pump onboard which does quick work of that.

[schoonerdog]

We previously had a Yamaha 20 hp 4 stroke engine, and it would bring 4 adults and 2 kids just barely onto a plane, maybe 8 knots or so. I expect the 25 hp which is now just a little bit more weight than the 15 - 20 hp engine can probably do around 13-14 knots. To me the biggest benefit will hopefully be the electric fuel injection.

[ausaviator]

I'm surprised a little by your numbers there schoonerdog.

I'm running a 4.25m PVC cheap Chinese inflatable on a 25hp Mercury 2-stroke. We hit a maximum of around 30 knots and that's with 2 adults and 2 kids, so a payload of around 250 kg's. Arguably the Chinese inflatables are sometimes heavier than the name brands.

Would that be prop related do you think or are the 4-strokes lesser performing. My engine weight is around 115 lb's.

[schoonerdog]

Originally Posted by ausaviator

I'm surprised a little by your numbers there schoonerdog.

I'm running a 4.25m PVC cheap Chinese inflatable on a 25hp Mercury 2-stroke. We hit a maximum of around 30 knots and that's with 2 adults and 2 kids, so a payload of around 250 kg's. Arguably the Chinese inflatables are sometimes heavier than the name brands.

Would that be prop related do you think or are the 4-strokes lesser performing. My engine weight is around 115 lb's.

Sorry about taking such a long time to respond, I don't get on as much as I used to. I can't imagine doing 30 knots, with just me on the boat I did 25 knots and it felt suicidal. Again, with just me on the boat, I can get up to around a nice comfortable and controlled 15 knots at 1/3 throttle. When I got up to 20 knots with the entire family they were all hunkered down and wanting off the boat! Then again, I'm motoring on the Chesapeake, so it's always got a bit of wave action. Maybe if I were on a nice calm river then it wouldn't seem so insane. Also, your dinghy is substantially bigger, so that probably has a bit to do with it. A friend has a 16 ft boston whaler with a 40hp engine 2 stroke and it can barely get two adults up on a plane, so there is a lot of voodoo for speed that I don't even sort of understand.

[a64pilot]

My Suzuki 20 HP with an 11” SS Solas prop would push my Zodiac 3.10 at mid 30 kt speed with just me aboard.
We now have a slightly larger aluminum AB, same engine and prop, AB is much lighter. Speed is now mid to high 20’s. Lighter Boat almost 10 kts slower.
AB is much deeper V, much better riding Boat, but much slower.
Boat hull matters greatly in speed.

[CaptNemoO2]

Originally Posted by schoonerdog

Sorry about taking such a long time to respond, I don't get on as much as I used to. I can't imagine doing 30 knots, with just me on the boat I did 25 knots and it felt suicidal. Again, with just me on the boat, I can get up to around a nice comfortable and controlled 15 knots at 1/3 throttle. When I got up to 20 knots with the entire family they were all hunkered down and wanting off the boat! Then again, I'm motoring on the Chesapeake, so it's always got a bit of wave action. Maybe if I were on a nice calm river then it wouldn't seem so insane. Also, your dinghy is substantially bigger, so that probably has a bit to do with it. A friend has a 16 ft boston whaler with a 40hp engine 2 stroke and it can barely get two adults up on a plane, so there is a lot of voodoo for speed that I don't even sort of understand.

I have the same boat, but i installed a console and steering, using a Mercury 25hp two stroke. I max out around 25 knots, I doubt my 25 is really a 25 anymore as its kind of on life support. This boat has an incredible amount of chine walk. I added automatic gas spring trim tabs, and it helped a little with the chine walk and is a little less scary. It really helped to keep the bow down when getting up on plane.