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Low RPM'S at wot

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nightstalker

Regular Contributor
Had a problem with port 1990 454 Crusader stalling at the normal low idle of 600 RPM'S. Seemed to smooth out at the dock, so I took her out for a cruise today. She idled fine and ran well throughout all RPM ranges until I tried WOT. The port engine wouldn't rev up past 3400 at first and then starting surging between 3400 and 3800 which was all the RPM'S I could get out of it. Starboard Crusader at WOT was pegged at 4400 RPM'S. I tried WOT a few times with no change on the port engine. I brought both Crusaders back to 3200 RPM'S for 15 minutes. When I tried WOT after the 15 minutes, the port engine jumped right up to 4400 RPM'S just like the Starboard engine. I tried WOT several times more during the cruise and she ran fine throughtout all of the RPM ranges. The idle is also fine now. Anyone got any ideas why it would do that?
Nightstalker
 
Last edited:
Tons of reasons preventing WOT. You need to start with one system at a time and eliminate possibilities. Last time fuel filter changed, including the one in the carb if applicable, and carb serviced? Last time tune up done, including dwell check if applicable, timing and advance? These are the first two systems I would look at? Fuel system could include checking everything from the tank to the engine including the anti-siphon valve, pick-up, pump, lines etc. If she starts acting up again, be prepared and hook up a portable fuel tank rigth to the fuel pump and run it. If she always runs good afterward, then the problem is before the engine. Be careful here; shut the fuel off at the vessel's tank or cap off the fuel line properly and ventilate. Let us know what you find.
 
Thanks for the info. Filters are new, also, recent tune, but I could have screwed something up as usual. I'll start with the carb and go from there. Didn't think of the timing issues. I'm going to be prepared with an auxilary fuel tank if she acts up again to check the fuel issues too. Thanks again for the help. Nightstalker
WoodieMan said:
Tons of reasons preventing WOT. You need to start with one system at a time and eliminate possibilities. Last time fuel filter changed, including the one in the carb if applicable, and carb serviced? Last time tune up done, including dwell check if applicable, timing and advance? These are the first two systems I would look at? Fuel system could include checking everything from the tank to the engine including the anti-siphon valve, pick-up, pump, lines etc. If she starts acting up again, be prepared and hook up a portable fuel tank rigth to the fuel pump and run it. If she always runs good afterward, then the problem is before the engine. Be careful here; shut the fuel off at the vessel's tank or cap off the fuel line properly and ventilate. Let us know what you find.
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