I guess the engine has been in for a month now, and the first three weeks starting in the yard every 4-5 days, the engine had a very clean response when i hit the throttles..
Finally this week since i was going to go for the first run on the water, i started it and it sounded like it was either too rich or not getting enough gas, the sound was not as crisp as before and even if it clear it would still do the same thing.
i changed the plugs and it still did the same thing. i went for the first run last friday, and the boat starts fine idles fine, but when i engaged it either in forward or reverse, it lost rpms quickly and would cut out. i really had to play with the throttles and almost time engaging the gear stick for it to not cut out which it done 9 out of 10 times, but when i was successful the boat cleared it self was was able to get on plane and run fine, but the minute i stopped and went to neutral and re shifted it would do the same thing. i've changed the plugs, checked the fuel filter for debris, fuel pressure guage says 6lbs of pressure..engine idles at about 800rpms
any ideas why this is happening, it idles fine but once u take the throttles from 2000rpms upwards, it stumbles and loses rpms, like it's going to cut out and then it catches itself and the rpms will rise..
and suggestions,
could it be my timing, or the the fuel filter was after the fuel pump, which i have now reversed..
'06 35 Lightning Merc HP 525's aka The Black Biotch
Sounds like carb set up is off to me. Check all the set up adjustments, the acclerator pumps, secondary throttle blades - make sure they are right vs the transfer slots, and then play with the idle mixture adjustment. Holleys are pretty simple carbs, but need to be set right or they can be fussy. Often in a boat motor with a larger cam this "stumble" going into gear deal takes some tinkering to work out, gets loaded by the prop.
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