I took this set up off a running bike (carb, pipe, cylinder, and intake,) rebuilt this motor (different engine) and slapped it on. Won’t idle unless the idle screw is cranked in and she’s screaming. Me no like. I took the carb off, tore it down. Soaked it in my bucket -o- carb clean for an hour and blew out every passage I could fit my nozzle into. Re assembled with an 81 main, 40 idle. Same result.
Blocked intake and exhaust, hooked up my leak down tester. No bubbles. I even took off the ignition and front vario to check the seals.
Checked my timing, marks were lining up perfect and to be honest If you hop on her and just rip it she fucking goessssss. Just won’t idle healthy at all. If I get it anywhere near the rpm I like, she stalls. I can almost get it to idle where I like with the choke (makes me realllly think it’s an air leak but can’t frighten find one)
Checked piston. Arrow is down to the exhaust like it’s supposed to be. (Never messed that one up but had to check)
Next logical step to me is put a different carb on to rule out the carb entirely, but other than a carb gremlin Or an air leak I cannot find even with a leak down, what on earth could cause this? It’s been a good long while since I’ve had to wrestle with an engine, and I thought I was covering all my bases, any ideas?