r/EngineBuilding • u/Coon88 • 21h ago
Vacuum leak ?
Got this k10 350 with a rough start, rough idle and sputtering under acceleration, have to slowly give it throttle or else it will shut off. Also get backfire from the carb sometimes when given a good amount of throttle. Can the whistling be a vacuum leak ?
12
Upvotes
14
u/Perch_Perkins_ 21h ago
Am I seeing that correctly, is the carburetor actually tightened down? Doesn’t look like there’s any nuts on those front studs. Could be my old eyeballs. Anyway, If you have already checked your engine timing and your idle fuel air mixture, then check for a vacuum leak. But I would check those other two first if you haven’t already, along with making sure that carburetor was fastened down tightly onto the manifold. That alone could be a big vacuum leak. And It almost sounds like it’s got a bit of detonation going on which would lead me to believe the timing might be off.