need to increase boost on planing

[Louis Miceli]

Hello all, i have a 1996 maxum with mechanical 8.3 cta 420 diamonds, 450 hours. Boat planes off slowly and has trouble getting over the hump. bottom is clean, after-coolers done Tony’s way last season, turbos rebuilt 30 hours ago, new fuel filters, 1 inch of pitch removed from props, new water pumps, air seps and belts, temps at cruise 160. I am getting black smoke as well only upon planing and some fuel in the water dockside. i have run it with engine hatches open and air seps removed with no difference as it seemed starved for air. I am thinking its getting too much fuel before turbos kick in and bogging down the motor. I am tempted to adjust the aneroid and am looking into CCV envirovent system. (although not sure if it would help). WOT 2650 before repitch, it will go over that now but i wont push it, the re-pitch helped somewhat but not solved the problem.
will CCV system help?
Nipsodenso pump aneroid adjustments info needed please?

thank you!

Topic

[Louis Miceli]

The Envirovent system is a whopping good product.– i have read the article about the b series what are the benefits on the c series?

[Louis Miceli]

Rob,

i see the fuel in the water before and after running, i smell the diesel heavy in the exhaust, it does smoke through same rpm range as planing when coming down off plane

[Louis Miceli]

The compressor side looks clean and do not see or hear any noticeable leaks.

[Rob Schepis]

Louis Miceli wrote:

and some fuel in the water dockside

Is this also noted when at full operating temperature, like coming down off plane to an idle when out on open water?
Or just upon initial startup or when cooled down backing into your slip after idling back into the harbor.

[donald roth]

Are you sure it’s fuel in the exhaust, or could it be motor oil?
The Envirovent system is a whopping good product.
Your motor will thank you, and it’s one more thing you could cross off your troubleshooting list.
Also make sure you are not overfilling the oil sump, read Tony’s article in “tips” section.

[Tony Athens]

These are very good questions to ask………….Let’s hope our poster can come back with something that makes some sense, & would be willing to check timing that way…(I would not hold your breath on that one) …………………………………………..But in the end, although he’ll be looking for something else, “history has shown” asking too much from the engine during this “getting up on top mode” would be where my money is placed…..

Tony

[Cato Jensen]

As you already seeing black smoke, I doubt adjusting the aneroid will do you any good.

Did you check for any charge air leaks? Does the turbocharger compressor look clean?

Finally, i’m thinking about injection pump timing. Has it been checked/adjusted? The plastic timing pin of the Nippondenso pump is unreliable and inaccurate, it is recommended to adjust timing using the spill port timing procedure.

What’s the RPM’s and the boost when you struggle over the hump? and at WOT?

[Tony Athens]

Only possible solutions.

1) Remove lots of weight

2) Prop way down– Maybe 2″ so the engine can spin up easy while you are trying to get over the hump..

I see this all the time on the early engines on 2-step hulls..

Again, no other solution.

Tony.

[Author]

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