Honda CB400SS Kick start and battery

[Kister]

Hi. my Son has bought himself a nice Honda 400SS. I am remotely trying to help him with a starting issue but I'm a bit out of my depth as I have a nice big battery and an electric start!
He has the age of bike that has a 2.5AH battery and to me it always seems flat ie the headlamp will fade to nothing once the bike stops.
I figure that this means that the Battery is holding little to no charge.
I'm also ASSuming that if he had a battery that held a charge. the bike would be easier to start as the volts wouldn't all be disappearing into an empty battery and a headlight that you can't turn off!
Can anyone enlighten me as to whether this age of bike is simply like this or whether the battery does need replacing once the normal charge and discharge tests are carried out?
Thanks
C

[stinkwheel]

Assuming this is the post-2000 hipster retro special?

I'd throw a battery into it.

The fact the headlamp comes on when the engine is run suggests the charging system is properly functional.

Sounds like the battery is utterly knackered. A more modern bike will need a certain amount of charge to power up the ignition.

A 2.5Ah battery costs next to nothing anyway.

Of course the best thing would be to do some actual testing with a voltmeter and see if it's holding a charge.

One caveat. The way this used to work in the 70's and 80's is the bike would have a seperate coil to produce the spark when kicked and the lighting ran directly from the engine (and went out when it was turned off) but I'm not aware of any post 2000 road bikes that work that way. It's possible Honda may have used the seperate charging coil thing in which case the battery is nothing to do with the engine running.

I can't find a wiring diagram for one (if you had one, I could tell you for sure) but they do appear to have a standard 5-wire regulator rectifier which suggests a conventional, battery-powered lighting system.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Robby]

Is it meant to have a battery that small? I only usually see 2.5Ah batteries on scooters.

I would replace the battery, but I would also make sure that the replacement is the correct battery. I would expect standard fit on that to be more like 8 or 10 Ah.

[stinkwheel]

[Kister]

Yes. Def the right size! Tiny little thing. New battery ordered. Thanks for the info on the possible separate charging coil.
Cheers!

[oilyrag]

Tell him to buy a trickle charger too or he will be buying a lot of batteries. Seems it has an immobiliser so a dead battery could cause issues there. He could buy the service manual from Japan. If the bike was only made for Japan there won't be an English version of the manual. https://page.auctions.yahoo.co.jp/jp/auction/u404619532

[Kister]

[oilyrag]

There's a wiring diagram https://imp.webike.net/diary/171390/

It has DC CDI so the battery is part of spark

[stinkwheel]

[mattsprattuk]

BCF: making dads seem more knowledgeable than they really are since wheneverthefuck
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Blue_SV650S wrote: it was a sh1te wheelie, but it proves that he can get it up in 3rd and can do angles. In summery, mattsprattuk is a gobby little sh1tebag, dopehead tw4t, but sadly for all of us, he probably isn't THAT full of sh1te!!
Kickstart wrote: Hi I tend to agree with Matt. All the best Keith

[Kister]