Any Yamaha Golf Cart mechanics in here ?

I have a 2010 gas cart, it sat for a long time before it came to be mine so I of course changed the oil and belts and plug and tires and basics. I ran a SHIT TON of sea foam through it and the engine runs fantastic now - I don’t even have to choke it to take off. ( NON EFI - it’s carburetor ). But it makes this sound I can’t identify at slower speed when accelerating and at night the lights flicker at the same time leading me to believe it’s the Gen/starter I am hearing. It’s like a whining sound like an old gear box (but it’s all fresh oil) and I feel like it has to do with the gen/alternator and or possibly the belt I replaced. It’s not normal what ever it is there are dozens of other carts just like it in my park (I am full time RV) none of them make the same sound. Any ideas for me ?