Okay, ran into a carb problem that has me a bit stumped, hopefully some of you can help with this.
Basics, 440, 11:1 compression, mild cam, dual plane intake, headers, Ebrock 750 carb. Even spent some time on a dyno and found out my old off idle bog was a lean spot while the rest of the range was fat. Stepped up the squirters, leaned out the rods, changed the rod springs and saw big power and mileage increases.I've been running this combo for years very successfully.
Over the winter I noticed I was developing a surge at part throttle. Kind of ingored it for a while until an hour long trip made the problem real unbearable. Under accelleration, it runs great, idle is smooth, but at part throttle, high vacuum cruise mode, it surges.
Tore in to the carb laast weekend, found the needle screens pretty gunked up with crud and sludge in the float bowls. Soaked everything in cleaner overnight, blew it all out the next day. Put it all back together, reset all critical dimension, put it back on and the problem was better, but still there. Wondering if it was a ignition issue, I put a 650 on and it ran fine.
So, what should I start looking at now? It seems odd to me that ht ecombo would just go sour, but thing can wear out I suppose. Thoughts?