Honda 1975 Honda CB500T DOHC won't hold charge.

[BrandonMurphy826]

So i'm new to this forum and am seeking help/advise with my bike. I have a 1975 CB500t. it wouldn't idle when i got it so i rebuilt the carbs and it idles perfectly. I've even rode it around my street a good few times. Where the problem comes in is when you shut it off and then try to start it again.
It will randomly not start (turns over extremely slow as if the battery is dead). sometimes this happens if i stall out the bike. other times i'll park, go inside for water, come back out to ride it around again and it won't start(turning over extremely slow.) i have looked under the seat at the starter and no wires are exposed. Also i just bought a new maintence free battery for the bike. If anyone can just point me in the right direction it would be much appreciated. I have an original service manual to reference but there's a lot of things to check. so i'm trying to get more opinions before i go checking everything.

[TOOLS1]

I would start with cleaning all the battery cable connections. Then I would check the charging system. After that would be the starter, especially if this is only happening after the engine gets hot.
TOOLS

[bohemiafens]

So the battery is new and off the correct amps, when it fails to start, try putting the battery on charge, to see if it is fully charged.

[Re-run]

I got a "brand new" battery once, had a short inside that read 12.6 volts on a meter but the second a load was placed on it, nothing. As Tools said, clean the battery connections, but also clean the connectors between the stator  and regulator/rectifier. Then, start the bike, hook up a meter and rev the bike to at least 2000 rpm, better to be at 2500 rpm. Your voltage should be 13-14 volts. If it is not, then if you have to stock regulator, try to adjust it and see if that helps.

Also, when you ride, keep in mind these bikes charge just about nothing below 2000 rpm, just the way they were made. Many of them also put out very few amps for charging, so short rides will really drain things. You should clean ALL connections, or replace them with new hardware. Changing to led bulbs can also help reduce load which helps with charging.

Anyways, if the charging checks out, then as Tools said, it could be the starter being hot and turning slowly.
Does the bike start fine with the kicker?