pen
CB750 Member
Alright, I bought this bike last year, it's a '78 cb750k. The previous owner was planning on having it be a cafe racer style bike. He was almost done, but encountered an "electrical problem" he told me. It did not run when I bought it. I spent that summer and winter tinkering, fixing, cleaning, breaking, and fixing again until I could finally ride this spring. I noticed the battery wasn't quite working as well as it should be, even after a full charge. So I went and bought a new one. The problem didn't go away.
I went online to see what the amp rating for the alternator should be on these bikes, as I thought there was potentially a ground leak somewhere. I had just installed a new electronic ignition and thought I might have messed something up somewhere. My search led me to a post on the sohc UK forum where they were talking about battery amperage. They mentioned that 14ah is the recommended size, with . It inspired me to look into the battery I have just to make sure I have an appropriate battery size for the bike. For reference, I bought a Duralast AZX5L, a variant of a YTX5L-BS battery. I did not know what the specs were on this battery before hand, but now that I do, I'm shocked it was running at all!
This battery is rated at 12v 4ah and 80cca! Really, it's no wonder I can't use the starter most of the time, why the battery dies when it's cold out and takes a little longer to kick start it. It's a scooter battery! All of this is to say, I need to find myself a battery that's small enough to fit in a tiny battery box (previous owner really did a bang up job with his cafe project) that also is suitable for this size of bike.
I went online to see what the amp rating for the alternator should be on these bikes, as I thought there was potentially a ground leak somewhere. I had just installed a new electronic ignition and thought I might have messed something up somewhere. My search led me to a post on the sohc UK forum where they were talking about battery amperage. They mentioned that 14ah is the recommended size, with . It inspired me to look into the battery I have just to make sure I have an appropriate battery size for the bike. For reference, I bought a Duralast AZX5L, a variant of a YTX5L-BS battery. I did not know what the specs were on this battery before hand, but now that I do, I'm shocked it was running at all!
This battery is rated at 12v 4ah and 80cca! Really, it's no wonder I can't use the starter most of the time, why the battery dies when it's cold out and takes a little longer to kick start it. It's a scooter battery! All of this is to say, I need to find myself a battery that's small enough to fit in a tiny battery box (previous owner really did a bang up job with his cafe project) that also is suitable for this size of bike.
