Okay, let’s talk about getting hands-on with the Yamaha 115 four-stroke and its weight. This came up for me not too long ago when I was helping a buddy rig his new-to-him boat.
Figuring Out the Heft
So, the boat came without a motor, and he’d scored a deal on a used Yamaha F115. Good motor, reliable stuff. But the first question that popped into my head, and his, was about the weight. We needed to know if the transom could really handle it, plus figure out how the heck we were gonna lift this thing into place.
First thing I did was grab my phone and do a quick search. You know how it is, you get conflicting numbers sometimes, different model years, shaft lengths, all that jazz. We also dug around for the specific model number on the motor itself. Found it, then cross-referenced online. Most sources were pointing to the same ballpark figure.
Then I remembered I had an old Yamaha brochure somewhere in the garage mess. Dug that out, and bingo. Found the specs section.
- Looked up the F115 model.
- Checked the shaft length – his was the 20-inch version.
- Found the weight listed right there.
It came out to around 377 pounds. Give or take a few depending on the exact variant, but that was the number we worked with. Almost 400 pounds hanging off the back of your boat – definitely something you need to consider.
Dealing with the Reality
Knowing the number is one thing, actually moving the motor is another. We didn’t have a proper engine hoist at his place. Initially, we thought, maybe three strong guys could muscle it? Yeah, bad idea. That’s a good way to hurt your back or drop a very expensive piece of machinery.
So, plan B. We ended up borrowing an engine hoist from another friend down the road. Getting the motor off the stand it came on and onto the hoist wasn’t too bad with the right lifting points. Slowly, carefully, we wheeled it over to the boat.
Lining it up with the transom mount holes took some patience. A little push here, a little nudge there. You really feel the density of it when you’re trying to make those small adjustments. It’s not just heavy; it’s awkwardly shaped weight too.
We got it bolted on eventually. Took a good chunk of the afternoon. Seeing it secured was a relief. It looked right on the boat, properly scaled. But yeah, handling nearly 400 pounds requires the right tools and a healthy dose of respect for gravity.
Final Thoughts
That 377 lbs is a solid number for a 115hp four-stroke. It’s way heavier than the old two-strokes of similar horsepower, which is a big factor if you’re repowering an older hull not designed for that kind of weight. For my buddy’s boat, the transom was rated for it, so no issues there. But the process definitely hammered home the importance of checking specs and planning the physical installation. Don’t try to be a hero lifting these things!
