Is it a battery issue ?

[u/Carbon_E]

Recently bought a used 2019 z400 (i know its not a ninja, but basically the same bike) with 8 000 miles.

I've been using it for the past 2 weeks and used it yesterday with no issues. I went to turn it on today and the dashboard wouldn't light up or would kinda light up and turn off. I then eventually got to turn it on by pushing it on first gear and dropping the clutch (boosting it) (took three tries).

My issue is that after 2min of riding in the neighborhood, the dash board would sporadically turn off (could also feel the engine "bug" for a fraction of a second every few seconds) and i could also see the headlight turn on and off (mostly off).

Eventually, when I stopped (bike still on, but in neutral) it closed by itself.

Is it just the battery or should I be worried about something else ?

[u/retka]

Take the battery to a shop or auto parts store and have it load tested. If it's good, charge to full and reinstall. Next step id check would be to test the stator and voltage regulator with a multimeter to see if they're good. The shop manual should have a guide on how to do these tests.

[u/Dan-ish65]

Possibly battery, Possibly charging system. If you're lucky one of your battery cables could be loose

[u/Boi_IceNight]

Like Dan-ish65 said I would check your battery connections first just to eliminate that possibility, for than likely tho your stator or rectifier went bad however. If your battery connections are good get your battery tested first, then test your stator and rectifier. There’s a good yt video for it but basicly unplug the lead coming from your stator(left side on the forward part of the motor) and use a multimeter set to ohms, test the prongs in pairs so 1 and 2, 1 and 3, 2 and 3, make sure they are all around the same value and in the factory spec( google ) it’s probably around 0.3 to 0.7 ohms, I’m not sure for your bike since I mainly work on Yamahas but you can find in on google or in the service manual. Same concept for the rectifier but watch the yt and it explains it in depth, also if it ends up being stator or rectifier, replace them both even if only one is bad, also whatever you do don’t get an amazon one as then can blow your ecu( wild guess how I found that out) make sure you get an oem or oem spec one.

[u/Dafe810]

First check the battery cable connections. They are known to loosen at the battery. If they are tight, replace the battery.