Mine started perfect, when richened with different rods from how they arrived.
Same setup with a buddy 1000' higher was a disaster. Another guy near him has the same deal. 50+ kicks to get it lit and then it idles like crap.
When it gets running right, like how I had them tuned, the pipe shook like a cat crapping razor blades!
The billet had some "upgrades" that it shouldnt have left the shop with, like the tip valve ball material/coating, float valve changes etc.
The cast, meh, wasn't too weird but i knew it needed a richer rod against their recommendation that it was proper as shipped. so it got here and i started it but couldnt use it really until a rod showed up 5 weeks after I got it ordered.
The carbs, no matter the clicker range or richness still get into a 3/4 throttle position lean detonation on deceleration. single circuit metering for ya.
The carbs weren't finished well, like it took messing with to get the cable in the slide and little things that could really tick a guy off at that kinda pricing. The cast was a dirty casting looking piece.
The billet had a really nice slide where the cast was machined with trailing marks which to a guy who makes chips for a living is kinda a tick off to see. These carbs are supposedly very closer tolerance etc, so why isnt the throttle valve lapped in, chromed, or just made right.
The SC guys i know have all gone back to standard PWK or pulse and all the sudden the bikes start, they run at any rpm and they don't fill the crankcase while sitting.
I think a pwk airstriker is much crisper low end, runs cleaner, and is substantially cheaper. The airstriker is a 38mm, flows the same as a 39/39.5/41 for cfm under 1/2 throttle, flows with less turbulence, more accurate metering and flows the same wfo, so its not really choking anything off, you can get to the jets without an allen wrench too.
Stick with stock, airstriker, or go Pulse.