86 Yamaha excel 3 charging problem

[Jdmranger4x4]

Hey everyone. I've got a 86 Yamaha excel 3 with some charging issues. It's got the 340 in it with electric start and pull cord. I can always start it with the pill rope. And I know the starter is bad so I've just used the pull start since I got it. Put in a new battery and it won't hold any kind of charge. These 2 stokes are a new breed to me and am just starting to learn them. Ive been a mechanic for 18 yrs and never really had any run ins with them. So what am I missing with the charging problem. Once it starts it runs fine and lights and all work perfectly. Just battery either isnt charging or won't hold a charge. I put a new battery in it this yr and have the same problem. Any guidance would be extremely helpful.

 

[archer]

You might start by putting your voltmeter across the battery terminals and see what the voltage is before you start and after, while its running. A charged battery should be somewhere between 12.8 and 13.2 and when charging should be 14 vdc or more. If the charge voltage doesnt change when its running, the sled has a bad charging circuit, maybe voltage regulator, CDI, diode, wiring, etc. If it seems to be charging when running but the battery discharges when its just sitting there I would think you have a component or wiring problem thats shorting to ground.