So, i recently bought a citation 4500 with a rotax 377, it is a points motor, single carb, 120 psi each side. I put new condensers in as it had a backfiring problem. It ran great for weeks after that. Just a couple days ago, throttle cable snapped and I replaced the whole throttle assembly with a throttle cable which had a rotax 277 slide and needle set up. It ran like garbage after and I just rode it like that for the rest of the day, not thinking much about it. When I was done riding, it started backfiring, but here’s the thing. It idled great and then when you press the gas, it backfires through the carb a bit but then it clears up and works fine. I realized I had the wrong slide and needle so I put the original needle and slide back on. Now it only backfires at idle but after you hit the gas to get past idle, it stops backfiring. I tried new plugs and I tore the engine apart to see if one of the condensers connections fell loose but they were all intact. I know quite a bit about 377’s as I have had them for years but this particular case has me stumped. Any ideas or help is GREATLY appreciated.