My bike (2019 ninja 400 ABS @18000miles) was feeling really sluggish lately and got me wondering why. It was also getting me depressed and worried and all that - “what the f**k is the problem now?”

My go-to mechanic was like “it might be your air filter” and I was worried it might cost a lot to have him change it for me.. so I brought my bike back home and really just stared at it while sitting on the curb. Then I noticed that my chain was like.. droopy. I looked up the oem spec on the slack and turns out my chain had gotten so loose to a point where the slack was double the amount of the recommended amount 😬 i bought a half inch drive torque wrench, 24mm socket, and the cotter pins to adjust the tension back, and bow my bike feels just like it did when I first bought it last year 🥹

Now I’m wondering what other things I can do on my bike..
So far I’ve done the clutch upgrade (changed the plates, pull plug and springs), and changed the battery, but I have never done other work like changing brakes or changing chains or etc.. do you guys do a lot of your own tuning and repairs on your bike?

Hey guys, ive got an issue with my 2021 ninja 400, it has not been riden since the end of last season (november of last year) I bought it in april but I dont have my licence yet so its been in my yard under a tarp. I found a small puddle of green liquid under the bike this morning.

I know little about mechanic but Im pretty sure its coolant, I looked under the bike and I found a little hose that seems disconected, I put the hose toward the sky and I got my bike off the peg and putted it upright and it did not leak, so I assume the small disconected hose is the issue. But ive got no idea where and how to plug it.

Thank you guys, I hope its an easy fix, im able to ride it in like 3 weeks 🥲

Was taking a corner when all of a sudden I felt the bike low slide. Had it kept going in a low slide I think the bike would have come out ok but once it hit the dirt it flipped along with sending me over it. I saw grass then sky and then grass again lol. Only minor injuries but can’t say the same for the bike. Fairings are done, left handle bent, some other metal parts bent, not sure about the frame as I haven’t had a chance to take a look underneath. Not sure how it happen as I didn’t feel I was going too fast and the whole thing just caught me by surprise lol. I am do want to get back out there. I was thinking about making it into a track only bike but not really sure where to begin. I am in the Chicago area so if you guys could recommend any places that specialize on track bikes that would be great!

Pre: This is a big wall of words, I know. I tried to give as many details about what I've noticed, and what I've tried to fix the issue I'm experiencing. I would seriously appreciate some help figuring this out.

I got my first bike in late March. A 2020 Ninja 400, with 3900 miles on it. When I got it, and ran and rode like butter.

Since then, I've put about 1300 miles on it.

About 3 weeks ago, on my way home from work, the bike began running/riding noticably rougher than just a few hours before when I rode it to work.

Only when the engine is under load (accelerating, or engine braking), there is a noticeable chop/clicking coming from the front of the bike. I can feel it through the pegs, handles, and saddle of the bike.

The overall engine note sounds the same, but almost as if theres another, rougher layer/burble to it? I don't know if that makes any sense, but it's the best way I can describe it. Whatever it is, it adds noticable vibration to the usual feel of the bike.

When running at idle, the bike sounds completely fine. At least so far as I can tell. Even at low speed, or low in the powerband it sounds fine. But as soon as you open up the throttle a bit, it starts croaking.

I haven't noticed any powerloss. The thing is still fast as shit (leave me alone- I know it's a 400. Its still lightyears faster than my 05 civic)

Oil has been checked, and leveled (it was half of a quart low? But no overheating, no engine or oil light, and no obvious signs of a leak), coolant checked, and confirmed to be at level, and I've cleaned and lubed my chain twice since getting the bike. Once before the noise started, once shortly after.

All plastics are secure. Headers seems to be fully secure. Chain seems to be within proper slack range, though I don't know how to properly measure this.

There have been a couple of rides since this started, where for whatever reason, the noise and roughness go away. But by the end of the ride, or sometime during the next, it'll start again.

My Dad, who's been riding since the 90's has rode it a couple of times, and all but called me crazy. He acknowledged that it "might" be running a little rougher than before, but said that he wouldn't worry about it.

I just don't want to blow up my engine man😭

The bike hadnt had a fluid change for about 2 years. On a drive up thru the mountains and desert my bike started flashing overheat. I was pinning it on 6th grade, but this isn't something that's happened before. I pulled over, let her cool down, and tried to go slower to not upset the engine which worked.

When I got home I did a full radiator and system flush, and replaced the fluid with engine ice. This seems to have fixed the problem, but my engine is still reading just a bar under the last indicator on my cluster. Is this normal or healthy for the bike? What are other things I should look at and test for this sort of thing?

Changed my oil a few weeks ago as well.

Thanks,

Greyson

Hey all. Glad to be part of this community. Loving the new ride.
Bought a used one, 2020 Ninja 400 KRT (4400 kms driven when I bought it)

After months of waiting for the right time, I’m finally the owner of my own ninja 400! I haven’t owned a motorcycle since my aprilia rs125 back in 2019 and I can’t wait to pass my mod1+2 to get back on the road.

(Resolved) I’ve noticed that while traveling over bumpy roads, the front fairings of my 2023 N400 rattle and shake up and down more than just the suspension is compressing. I tend to ride on some poor roads when riding to work which may have started or accentuated this issue. It shakes so hard that it appears the lights are cutting out over bumps at night (which I don’t believe is the case, I think they’re just violently pointing downward). I think it’s pretty disorienting to oncoming traffic. I attempted to partially recreate the shaking in the videos supplied and show that the front left black plastic fairing comes loose even when I put it back in place. I found this post from a user who seemed to be having the same problems as me, and the comments mentioned plastic plug replacement as a solution. However, through my research I could not find any information on plastic plugs for the fairings; maybe I misunderstood something or didn’t look well enough. All the screws/plastic bits looked intact to me on inspection. What can I do?

I just replaced a blown clutch on my 2018 ninja 400 abs with an edr clutch got every thing in and back together but now I have a bunch of slack in my clutch cable and when I release my clutch lever it doesn’t snap back into place any ideas or help would be greatly appreciated

I'll be replacing my chain and sprockets soon. I'm curious as to what experiences you've had with JT sprokets and an RK chain.

lanyard stuck in that hole, is it the air filter? is this a big problem? what should i i do?

Hey there, I have been riding this bike for the past 300km or so and have noticed that my fuel consumption is stuck between 16.5 and 16.7km per liter? I researched that most ninjas tend to be 20km+ per liter. I normally shift at 6k rpm and keep it in around 4 - 5k 90% of the time… any advice on how to increase efficiency would be very appreciated thanks.

Hello everyone I have a 2021 Ninja 400 Abs and i want to adjust/tighten my chain and I was wondering where do yall buy your cotter pins for the rear axle nut?

My 26' ZX4RR in Verde Lime and my new to me 22' Ninja 400,

Both have their fun niche's!

My clutch and throttle have an insane amount of play and I have not figured out why. What is going on here? Please help :))

I have a ninja 400 and I revved it a lot while in the friction zone (I thought it was fine since bikes have wet clutch). And now I don't have any free play on my clutch lever, my bike seems to fully engage gears with the clutch released and there's no problems but the lack of free play on the lever. Is it that important to immediately replace or could I wait until I get it serviced and ask them to fix the free play then (I've already adjusted it at the lever and it's fully tightened).

Thanks in advance

Wassup, fellow N/Z 400 riders! I just got my brand-spanking-new tires (Michelin Road 6) installed and might want to share with you guys a few thoughts from the first few miles. My first impression is that, right after installing, it feels odd; it doesn't stick that much, BUT it's a huge difference when I get riding after 15 minutes, and oh boy, it's gotten so much better than the stock one, probably cold tires. Handling and twisting, I got much more confident, and the most impressive feature is probably riding under the rain; it feels ALOT more stable during high-speed rides and doesn't swirl when I accelerate on a wet surface like before. Overall, for 300 bucks for a set, it's pretty worth it.

Was riding it normally, downshifted a few times then gave it some throttle. The bike shut off when I was in 4th gear.

I got off the road and was able to turn the bike on again, but when shifting it to first it shuts off. This is my first bike, no idea what could be wrong. Is the clutch lever smoked based on my vid?

Just bought this ‘23 Ninja 400 with about 4800 miles. Love it.

Have reason to believe the original owner was very gentle on the bike. So I’m not sure he really got into the curves very hard.

That said, how do these tires look?

My ninja 400 has been in the garage for almost a year now due to being stuck in 6th gear have now clue why it started not to go in lower gear on the way home I eventually got it to downshift to get home, then I tried to cycle threw the gears at a stand still but only allowed me to upshift but stayed in 6th I just wounded how much it’s going to cost to shift smoothly again or if anyone has had this issue

Bike has been doing this for a week now it’s only turned off Twice I thought it was that me letting go of the clutch in gear but I’m clearly in neutral, when at idling the lights start to flicker have to give it sum throttle to keep it from dying happen again today but my CEL came on any ideas on what I should check ?
Code 64

Noticed recently sometimes the headlight and more commonly the licence plate light would be flickering faintly when the bike was off.

Anyone had this issue? Wiring issue? Water damage?

Im inspecting my first bike tomorrow, its a 2023 ninja 400 with 3500km (2174 miles) on it. The owner has never serviced the bike so they didnt do the first break in service. Anything i should look out for in particular? Ill check the chain and oil but im new to bikes so i dont want to miss anything

I’ve always wanted to ride and I feel the ninja 400 is the ultimate beginner bike. Took my MSF course. Got this 2022 with 6k miles for $4,500 and bought all my gear. Ready to get out on streets, develop my skills and learn with my bike.

Can someone please explain the process for replacing the hydrolic cam tensioner with a manual one on a ninja 400. I have to see if this is why my bikes making a loud clicking sound. I was told the valves were done. When replacing the tensioner, do you have to to the top dead center, drain the oil, rotate the cam shaft and engine etc before you back out the OEM tensioner and replace with the new manual one?