My vlx600 is hissing when choked. I took off the choke cable in order to access the valve covers when checking the clearances and since then when I pull the choke cable it makes a hissing noise. And now I can’t tell if I’m imagining it or if it’s actually there but I feel like when I accelerate it’s slightly there. I’m gonna check the boots that come from the cylinders to see if that’s the problem. That being said, the bike runs really well and it isn’t overheating or stalling. If anyone finds the solution to this I’d love to know. If I find it I’ll post an update as well.