I have a 99 v-star 650 Im having issues with. So get into it, the bike was running awesome before I started any mods.
When I got the bike, it had a little bit of downshift popping. I did the hole mod in the exhaust. Didn't change performance, just sound.
I ordered the Sigma6 jet kit and the spike intake. After install, 0-1/2 throttle was way better, WOT was amazing. Midrange, not so much. I got hesitation like its falling on its face. I assume this is a lack of fuel because pulling out the choke nob fixes the hesitation. After a day, I added Cobra pipes which obviously didn't help the problem. Its not terrible, I just add some throttle and I can make it work. I went ahead and spaced the main jet another small silver washer, making it 1 nylon and 2 silver washers.
Im debating on putting another silver washer or 2 on each carb and see what it does. I feel like id rather be a little on the rich side than lean. Sigma suggested I order a bigger main jet, but as stated, the issue is 1/2 to 3/4 throttle. I always thought that was the needle. Things I haven't looked at are fuel filter and carb inlets(they are slightly cracked). As I said, I had 0 issues before jetting, intake and pipes. Any help would be great....Im going to look at exactly what size the jets are that came with the Sigma6 kit. Thanks in advance.