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Discussion Starter #1
I go through about a full quart of oil every 3 hours while cruising around 3500 rpm with a quick WOT run every now and then. After sitting a while i do see some blue smoke at start up, but never while running on the lake. Still have good oil preassure, valve cover breathers are clean and i still get 65mph @ 4800 rpm with an A impeller with no hesitations at all. So am i looking at bad valve guides/seals? or could it still be the piston rings?
 

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I go through about a full quart of oil every 3 hours while cruising around 3500 rpm with a quick WOT run every now and then. After sitting a while i do see some blue smoke at start up, but never while running on the lake. Still have good oil preassure, valve cover breathers are clean and i still get 65mph @ 4800 rpm with an A impeller with no hesitations at all. So am i looking at bad valve guides/seals? or could it still be the piston rings?
Unless your rings are toast...I would bet it is a sucked intake gasket if it has an aluminum intake....Just a bold ambitious shot in the dark.:D

GT :)hand
 

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Smoke at start up usually is caused by worn seals or guides, or both.
Yep. I'll bet the valves have plenty of oil deposits on the tops if you have many hours on it.
 

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Discussion Starter #5
the thing is the boat only has 70 hours on it, but it was built in 1995. the first owner had the boat built by ultra custom boats then he sold it to a friend who also took great care of it...THEN that guy sold it to someone who knew nothing about boats, the boat was used twice in 3 years and it just sat in his driveway. the starter was rusted solid and the carb was toast when i bought the boat. Its just a stock 340hp marine power 454 with the peanut port heads, so im not opposed to using the oil problem as an excuse to get new heads and intake haha. i used 30w on my first trip out, i changed the oil when i got back and put in 40w with lucus additive, even with adding 2 quarts a day the oil was BLACK.
 

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the thing is the boat only has 70 hours on it, but it was built in 1995. the first owner had the boat built by ultra custom boats then he sold it to a friend who also took great care of it...THEN that guy sold it to someone who knew nothing about boats, the boat was used twice in 3 years and it just sat in his driveway. the starter was rusted solid and the carb was toast when i bought the boat. Its just a stock 340hp marine power 454 with the peanut port heads, so im not opposed to using the oil problem as an excuse to get new heads and intake haha. i used 30w on my first trip out, i changed the oil when i got back and put in 40w with lucus additive, even with adding 2 quarts a day the oil was BLACK.


Whoa, that's a ton of oil. What do the plugs look like? Are any an oily mess? I'd do a compression and leakdown.



Darrell.
 

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Discussion Starter #7
I'm not at home so i cant check anything myself, i have to wait til the boat can be taken to a shop. but i know the spark plugs were darker then they should be. given that i get blue smoke at start up, but none noticeable while on the lake. and the boat sat for god knows how long, and i have absolutely no oil in my breather filter after running it hard for 3 days. my best guess is the valve seals went bad after sitting for so long. of course ill check everything else before just slapping new heads on(peanut port heads, arnt worth fixing) but i hope this is the problem.
 
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