I maxed out at about 3,500 RPM's and 19knots which is about 5-6k lower than normal. Something is up so here is what I've done so far. It seems to be the exact same issue on both engines.
Engines are carb'd 454's, 1988 with about 1,400 hours. Neither engine uses any oil, no smoke and run like a top. I have owned the boat for eight seasons so good year to year history to look back on.
1) TA timing is 32 degrees at 3,200
2) installed new HEI distributors, plugs, cap/rotor and wires, no change
3) changed my pre filter screens, Racor and carb filters. Also, just rebuilt stb carb last week (didn't really need it).
4) chokes are wired open on both engines
5) verified that the engine will exceed 4,000 RPM's in neutral and that tach will read that high. Got to around 4,400 and pulled throttle back because I hate to run it that high with no load
6) flame arresstors were just cleaned
9) verified that the throttle cable aligns to the carb at WOT
10) did WOT test with gas caps removed to verify no vent issue
11) removed anti-siphon valve, perfectly clean
12) Temps, oil pressure spot on, oil is clean
13) shafts/rudders/props all clean (dove under to verify this weekend). Diver is checking bottom tmrw but not expecting anything but would be thrilled if this was the issue.
14) hull is not cored so no weight gain
15) on my 3rd tank of fuel now, no changes throughout
Start up, idle and throttle up all have been and continue to be perfect. Not even the slightest feeling of an issue until you open it up.
When I put the boat away last year it would get to around 4,200.
What do you guys think, I'm a little stumped.
Thanks,
Bob
Engines are carb'd 454's, 1988 with about 1,400 hours. Neither engine uses any oil, no smoke and run like a top. I have owned the boat for eight seasons so good year to year history to look back on.
1) TA timing is 32 degrees at 3,200
2) installed new HEI distributors, plugs, cap/rotor and wires, no change
3) changed my pre filter screens, Racor and carb filters. Also, just rebuilt stb carb last week (didn't really need it).
4) chokes are wired open on both engines
5) verified that the engine will exceed 4,000 RPM's in neutral and that tach will read that high. Got to around 4,400 and pulled throttle back because I hate to run it that high with no load
6) flame arresstors were just cleaned
9) verified that the throttle cable aligns to the carb at WOT
10) did WOT test with gas caps removed to verify no vent issue
11) removed anti-siphon valve, perfectly clean
12) Temps, oil pressure spot on, oil is clean
13) shafts/rudders/props all clean (dove under to verify this weekend). Diver is checking bottom tmrw but not expecting anything but would be thrilled if this was the issue.
14) hull is not cored so no weight gain
15) on my 3rd tank of fuel now, no changes throughout
Start up, idle and throttle up all have been and continue to be perfect. Not even the slightest feeling of an issue until you open it up.
When I put the boat away last year it would get to around 4,200.
What do you guys think, I'm a little stumped.
Thanks,
Bob