As mentioned in my other post, I picked up a 2018 Ninja 400 recently. I've been looking at them since they came out earlier this year. I've always preferred the newer styling of the recent Ninjettes, but the 500 is the smallest bike I've owned (barely, of a relatively small number of bikes). The 250 really was about half the power of the 500. The 300 had EFI and a decent bump in power, but was still quite low compared to the 500. I liked them, but they just seemed like too much of a downgrade. I'm a bigger guy and I live out in the boonies a bit, not deep in the big city. I liked having the power of the 500 when I needed it.
When the 400 came out, the power numbers were getting closer to the 500's to where it could be more of a sidegrade. It had a lot of features I wanted, like EFI, LED lighting, and the modern styling. I was hopeful that the EFI and lower weight would help counter the decrease in raw horsepower. I put off looking at it because I didn't figure it would be sufficient, and my 500 is my baby that I've put a ton of TLC into.
Early this month I had some time off work and decided to go check out the 400 in person. I went into it expecting it to be a downgrade, but hoping it wouldn't be too noticeable. I was surprised at how much I didn't notice the drop in power. I think I notice the drop in torque the most - it doesn't feel like the acceleration is pushing you off the back as much. But somehow, it seems to actually get up to speed more quickly. I'm used to the Sarachus now, so the 400's stock exhaust sounds very different, on top of the differences in the engine itself. It sounds higher-pitched and whinier (but in a good supersport way), so it sounds like it's working a lot harder, though it seems to have pretty similar output overall. If I stop to think about it, I know it has less power, but in actual riding I've never really felt like it's lacking compared to the 500. I'm still somewhat amazed at how it doesn't seem like less power.
Whereas the 500 has a pretty noticeable drop off after peak power, the 400 does a better job of maintaining power up to the redline.
Overall, I'm very happy with the bike in stock form. It works well out of the box. There are no huge issues that I feel should be fixed right away. The suspension isn't as good as my 500 with $700 of mods (more like $1100 if I had bought the Penske new), but it's miles ahead of the 500's stock suspension. It's a basic suspension made for the general population, so it needs tweaking for my weight and there are definitely improvements possible. But I'm just as comfortable pushing the stock 400 hard as I am pushing my modded 500. I'm surprised by how light and flickable the 400 feels. I'm not sure if it's steering geometry or center of gravity or what, but it feels like it turns just by thinking about it. The design of the tank fits my larger body much better. I'm still a relatively big guy on a relatively small bike, but the design isn't as unforgiving for fitting my legs. It comes with a floating front rotor, light wheels with thin spokes, and a 150/60 out back - very similar to what I spent over $900 adding to my 500. The mirrors work just as well as the larger 250J mirrors I put on my 500. Plus they swing at the base with detents, so it's easy to tuck them in for parking without having to readjust them every time. It's still got the empty threaded hole on the clutch perch where you can mount something, and it's got a hollow steering stem so you can use the RAM mount made for that. The LED headlight gives a pretty nice pattern (the bright white light takes a bit of getting used to). I'm currently averaging 6mpg more than on the 500.
I love the dash. The backlight for the tach needle changes from white to red when you hit the redline, so the needle actually turns red. The gear indicator is nice for making sure you're in the right gear, especially while you're getting used to how a new bike shifts (though I still tend to remember what gear I'm in anyway). The digital speedo is fed off the rear wheel (it has an ABS-like ring) so I can change the sprockets without having to monkey with that. I still don't fully trust the gas gauge since it's such a small tank and there are only a few segments making up the gauge - there's not a lot of room for precision representation there. I love having a clock visible right there. The MPG gauge is neat, though I've used it mostly for comparing different riding styles out of curiosity. I've already gotten used to having more info, to the point I wish it had a few more things like air temperature. There's even a built-in spot to add a power socket.
Now I'll get to the complaints, which I consider to be pretty minor. The gas tank is only 3.7 gallons. With EFI, I'm a little more wary of running out of gas, so I stop more frequently than with the 500's 4.8 gallon tank. I still get ~175mi per tank, so it's not horrible, just a little less than I'm used to. Especially for my size 12.5 feet, the muffler is close to your heel. It's got a shield there, so it's not a huge issue, but you may bump it occasionally. One of my bigger gripes is that it doesn't have a centerstand. You really get used to having one of those. It's great being able to just toss it up on the centerstand to have it upright and get the rear wheel up for maintenance. Most sportbikes don't have one now, so it's not really unexpected, but you realize how much you miss the centerstand when it's gone.
A couple other little things... They use LED headlight and taillight assemblies, but still put regular bulbs in the turn signals and plate light. So that was another $40 for a new flasher relay and some good LEDs. Kawasaki's power socket for the dash is ungodly overpriced. The standard 12V lighter socket with a couple inches of wire is $85, plus you have to buy a $25 relay to plug into the wiring harness to actually get power to the accessory wires. I accomplished the same thing (actually better, for me) with a $12 dual USB charger and a generic $4 relay. The swingarm has spool mounts, but they're 8mm instead of 10mm like the older Ninjettes. Not a huge issue, just a change that could catch some previous owners off guard. The clutch is a super light pull - with the stock levers it was easy to accidentally pull it a bit with my fingertips when I was just covering the clutch between shifts. Again, not necessarily bad, but quite a change from my 500 with upgraded clutch springs.
I already got a fender eliminator and shorty levers, and swapped over my heavy bar ends. I need to get some OEM plugs to add the brake light flasher. I plan to get a double bubble windscreen. Whereas the 500's windscreen was about even with my shoulders in riding position, the 400's is about even with the bottom of my sternum. I'll probably get a Power Commander eventually, because I can't not mess with things. It's likely I'll eventually get an exhaust too, possibly a full setup so I can slap in the PC AutoTune.
After three weeks and about 950 miles, my verdict is that this bike is basically what I wanted my 500 to be from the start. It has the modern looks and technology that I've been missing. It has some upgrades inspired by bigger bikes. It's a bit smaller, but I'd say it manages to perform just as well as the 500 (better in some cases). They managed to keep it the same price as the 300 even. If in a few years they manage to get it up to 500cc and the same dyno numbers as the current EX500 for a similar price, it will be an amazing bike, and I'll be very jealous and/or at the dealership discussing trades. For now, the EX400H is doing a great job of keeping me happy. For anyone looking at buying a 500 cheap and doing a lot of upgrades to make it more modern, I have to suggest at least considering the 400 first.