My 08 busa won’t start

[Huntercs10]

Okay so recently I was riding my busa to Home Depot and on the ride there I noticed that my dash lights were very dim but I really thought nothing of it. So I got to Home Depot, got some things and when I came outside and went to start it up it wasn’t even trying to turn over.
I’ve had some battery issues the day before but I charged it and so I thought it was fine. Could this be a result of a bad battery or a starter issue?

 

[Skyvie]

I've seen batteries go out abruptly, so it could be that, especially if you haven't replaced it recently. You did mention the lights getting dim. In my experience, starter issues don't just pop up. I'd check that the battery connections are tight, and then check the battery with a voltmeter with the bike off and the bike on.

 

[Bumblebee]

It's either a bad ground or a battery that went for a dump...

Check your battery leads and terminals and make sure they are squeaky clean

 

[mabupa]

Since it’s a 2008, did you ever get the rectifier recall done? Might just be a dead battery, but a load test could confirm that.

 

[michael parris heuberger]

Since it’s a 2008, did you ever get the rectifier recall done? Might just be a dead battery, but a load test could confirm that.

Hi. After you charge and load test battery start bike and check stator output.

 

[Mythos]

Based on the dimming issue and the fact you had to charge the battery the day before, I'd lay my money on battery. An old battery often gives the sign it's time to replace when it doesn't hold a charge.

Could be the alternator has a problem too. If the battery is old, probably it's that. Charge it up and see if it starts the bike a couple days later. If not, it's the battery. If it starts and then dies after a ride, it's the alternator not doing it's job.

Was the rectifier recall taken advantage of? The factory rectifier on the 08 had issues.

Still got my factory rectifier and battery 11 years later and it runs just fine. I'm seriously considering putting in a new battery though. The one I replaced on my other bike just shorted out all the sudden. Good thing that was at home.

 

[HayaWakened]

 

[Mythos]

Definitely recommend one of the lightweight batteries that have come on the market in the last several years. My Shorai is still kickin after 10 years and it weighs 1.25 lbs. Starting to drop in voltage too much to start after 6 or seven days but fine as long as I ride often. I'm know they are making batteries lighter than this now. Get recommendations on what is reliable.

 

[Kiwi Rider]

Battery and charging system output test

1st, charge the battery then start the bike and run it with a multimeter switched to volts attached to the battery terminals, also check the terminals are secure.

If the charging rate is reading 13v or more, you have a battery problem, replace it.

If the voltage is around 12v, the charging system is not working and the stator output on all 3 phases must be checked for AC voltage to be within spec. (around 20v AC at idle, 70-100v AC at 5000rpm)

Check all wiring from the stator to the regulator/rectifier, especially the connector plugs for overheating/melting.

If the stator is ok then the voltage regulator/rectifier has failed and needs replacing.
Simple as that.