Reply With Quotebe careful! If it starts pinging, back the timing down. It would definitely be worth the distributor change though.
I have a 1988 Carrera Caliente with a mostly stock Hardin Marine 454 (330 hp) with log manifolds and I think the size of the 4 barrel carb is a 850 cfm. I am still running the mallory distributor that has points. The boat has 150 hours on it and I don't think the point have never been set or replaced. I have had the berkley pump done by MPD (stage 2.5). The engine doesn't labor at all and engine never revs above 4200 rpm. I am running the stock aluminum impeller that MPD has reworked. At 4200 RPM I am neck to neck with 60+ mile per hour PWC. Sounds too good to be true. I know there is more rpm to be had out of the motor.
I am considering installing a DUI distributor, increasing the spark plug gap, and possibly increasing the advance on the ignition timing.
Will these mods help with getting the rpm up?
be careful! If it starts pinging, back the timing down. It would definitely be worth the distributor change though.
Just one unrelated point... the stock carb. for your motor was a 650 CFM Marine Holley
Never above 4200 RPM AND running at 60+ MPH AND a stock motor - :argue:
I have a similar setup, 87 Commander 21 footer open bow 454 hardin marine 325 hp, AT AA imp, inducer and stuffer, edelbrock rpm airgap holley 750 4160 carb with spacer dual points with super coil and just did 58.8 GPSed with half load of fuel, anchors, dual batteries and 60lbs of tools turning 4200rpm and it has the peanut smog heads.Not too bad for a big heavy.Timing is 32 deg total at 3000 rpm. Let me know if you do the ignition and see improvment but use a gps to verify actual speed before and after so you can see the actual increase or decrease.
be careful! If it starts pinging, back the timing down. It would definitely be worth the distributor change though.
Thanks lilrick I'll keep that in mind. Any idea of how much I can advance the timing without encountering any problems?
Never above 4200 RPM AND running at 60+ MPH AND a stock motor - :argue:
Probablecause - I probably should confirm that with GPS. If I'm not over 60, I'm close to it.
I have a similar setup, 87 Commander 21 footer open bow 454 hardin marine 325 hp, AT AA imp, inducer and stuffer, edelbrock rpm airgap holley 750 4160 carb with spacer dual points with super coil and just did 58.8 GPSed with half load of fuel, anchors, dual batteries and 60lbs of tools turning 4200rpm and it has the peanut smog heads.Not too bad for a big heavy.Timing is 32 deg total at 3000 rpm. Let me know if you do the ignition and see improvment but use a gps to verify actual speed before and after so you can see the actual increase or decrease.
Bighead - I'll keep you posted on what type of results I get from the hei distributor. I just need to get my hands on a good hand held GPS. Can you recommend a good one?
This past weekend I was towing skiers. When I'd jump on it to get them out of the water, sometimes, I'd get a pop coming from the carb. I'm thinking its just an ignition problem. Does that diagnosis sound right to any of you?
I have a Garmin handheld one and it does work fine, I think you can pick up a handheld these days for under 200 bucks at just about any electronics or sporting goods store.You will be suprised at what it will tell you and anyone else who will make a couple of runs with it, it is a humbler for sure.
Posting Permissions