Just looking for some ideas here, been chasing this problem for close to 4 months. This has literally driven me nuts. Please help!
Boat fires and idles perfect. Accelerates and cruises just great. When hammered it picks up pretty good then quits about 4800 and just kinda bangs...peters out. It just ain't right.
19' Daytona jet berkeley pump A/B with all the goodies
477 BBC 9.5-1 fresh only time on this thing was breaking in cam on test stand and maybe 5 hrs
063 ovals mild port work
Duration @ .050 241/249 .572/.590 LSA/ICL: 110/106 hydraulic flat
I have tried:
replaced all power grounds, cables and switches.
3 ignition setups, MSD and HEI (including running hot wire straight to battery) wires, plugs...
3 carbs from running engines with similar setups
used gas can straight to holley blue to carbs pressure never moves off 7 and bowls are staying full
adjusted valves 2 different methods EOIC and TDC tried from zero to zero plus 1/2
had valve springs tested
pulled engine and degreed cam
shut off all water to headers