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malibu's making oil


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check out skifly.com message board under skifly gossip, read the engine oil thread.

has anyone heard of this or had it happen themselves. Mad.gif

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Sounds like fuel is getting into his engine.

I agree. My '97 VLX with a Monsoon 320 (injected) would be a quart high at the end of the season (which is 80 hours or so for us). I assumed it was fuel, but the boat ran perfect, started great hot or cold (if the injectors were still spraying fuel for a period after the engine shut off, as was suggested in the other thread, the engine would restart hot poorly, as if it were flooded). Idid not try to find the "problem", I assumed it was a bit rich of a mixture at low engine speeds due to the absence of an O2 sensor.

My current boat with the Monsoon does not have the problem.

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Should be NO way for excess fuel to get into the oil.

Could be water getting in through a failed head gasket.

Or could be the difference between the oil level when leasured in your driveway, vs. the level when measured in the water.

I always leave mine a bit low in the driveway and top it up on the water.

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'dog,

Fuel can get into the oil easily exactly the way Hman said. It's quite common actually if the injectors are leaking. Hman is also correct that the 2000 boats run pretty rich if you ask me. So, I wouldn't be surprised if fuel got in the oil. On the plus side, the fuel would burn off very quickly once the boat got hot and ran for awhile.

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Agreed. I've seen this too in cars with a bad tune. I've had tunes that were off the mark that gave eye watering results out the tailpipes, and a lot of excess fuel ending up in the oil. When you dump the oil, it reaks like raw fuel.

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Have an analysis done on the oil at the end of next season. You can have it done at a place called Blackstone Labs. Search for them on the web. If there is anything in the oil they can tell you. You also find out how the oil did in the motor, and how the motor did with that oil.

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That makes sense to me.

Just another reason to not ski at a private ski lake. Take her out to the real world and open her up. I drive my boat at W.O.T. for a little bit every day it's on the water. (usually while racing another boat)

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And winning???

Of course. Malibus blow right by the CC, MC and Moombas. My Sporty goes as fast as a SN without even getting into the secondaries.

Edited by 88Skier
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Master Toad is right on the money.

First off, the skifly boys are running their engine as hard as possible, on short sites and big engines. Hammerheads, 8.1's, bigger the better. All these add up to fuel in the oil.

The tournament drivers running exlusively in small sites REALLY should run a higher thermostat and change their oil every 25 hours max. With the cool 160* temp thermostat, and the 16 sec's of rpm the engine gets per pass with a idle state at each end, the oil never gets a chance to completely get up to temperature and burn off any fuel that is blown by.

You might not know it, but every engine has this happen, it's just the crankcase gets hot enough to burn off (evaporate out) any excess fuel in the oil.

So run her hard, but don't put it away wet.

Peter :)

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OK, can someone explain in english why boats on private sites get more gas in the oil?

Why is it that we have such cool thermostats?

Why is it that peter says not to "put her away wet"...I assume that's engine-speak, not literal

I'm really getting confused actually...Peter, are you saying teh harder you run (like the skiflyers) the more gas in your oil?

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I have no experience on private ski lakes, but I'm assuming based on the above comments that the problem is that they are just REAL SMALL. IE, you make a pass through the balls and then have to stop real quick before running aground. So, in such a small area, you never have a chance to run the boat at speed for more than the length of the course. It takes heat to burn the fuel out of the oil. If you get your boat out on a big lake and drive it for longer distances, you accomplish this. But when you run a course for 25 seconds, and then idle for several minutes picking up the skier, dropping off a new one, etc. and then run for 25 seconds again, and repeat this thousands of time through a season, you aren't getting the oil hot enough to burn off the fuel like a normal boat would.

As for the stat, and again I'm speculating, they put the 160 stat in there simply because they can, and the engine will run at that temp. In general, heat robs power. So the cooler you can keep it running, the better it should perform. It would do no good to put a 160 stat in a car, because on a closed cooling system and finite sized radiator, the car just won't run at 160 because the radiator and fan can't cool the fluid fast enough. You can put a 160 in a car and it will still run at 180-190 I bet, and the stat will stay wide open. With your boat on an infinite radiator (lake), this can be accomplished much easier. Just my theory though.

And also when an engine is run hard, the oil temps will be higher than the coolant temps. This helps the burn-off idea Peter mentioned.

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BillFooters Hammerhead, has done this several times. Doesn't matter how he runs it. We only barefoot and it gets the piss ran out of it and still does it. I think it is from a injector leaking down while parked. It would have to be flooding it's butt off to get enough past the rings to overfill the crankcase while running. Basically it wouldn't run good. Black smoke and soot up the back of the boat and even miss and foul plugs.

My guess is a injector or injector's dripping after shutdown. It wouldn't be excessive or it would cause a hydraulic lock, but just enough to leak past the rings.

That's my theory....but,I could be wrong.

Edited by Sunset_Bob
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That makes sense to me.

Just another reason to not ski at a private ski lake. Take her out to the real world and open her up. I drive my boat at W.O.T. for a little bit every day it's on the water. (usually while racing another boat)

At the very least it's a plug for breaking in the boat in open water. Even if you ski it right out of the box it will have some time at mid rpm under load to get the rings seated properly. Once that's done I don't see why a boat couldn't spend many uneventful years on confined water.

I don't see how you can break in an engine properly on confined water, whether you use the Indmar or PCM method.

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As Sunset Bob said the oil level increases in my 2000 Hammerhead. After about 30 hours the oil level is about a quart over full. The oil also smells very storng of gas. I read a thread a long while back that a faulty water temp sender that sends the signal to the ECU could cause this.

Peter, is that possible??

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That makes sense to me.

Just another reason to not ski at a private ski lake. Take her out to the real world and open her up. I drive my boat at W.O.T. for a little bit every day it's on the water. (usually while racing another boat)

At the very least it's a plug for breaking in the boat in open water. Even if you ski it right out of the box it will have some time at mid rpm under load to get the rings seated properly. Once that's done I don't see why a boat couldn't spend many uneventful years on confined water.

I don't see how you can break in an engine properly on confined water, whether you use the Indmar or PCM method.

Well even on most private sites you can get 25 seconds of running real hard

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Stuck thermostat, Bad temp sender, Bad MAP sensor, Bad fuel regulator - all will create a rich condition helping to flood the crankcase with fuel.

The other situation is that GM switched to a "low tension ring" a number of years ago to increase fuel economy, and this has caused rings in the marine industry to get stuck, therefore allowing fuel to wash the cylinders down. There is a "piston ring cleaner kit" available from your dealer for about $100, that may unstick any stuck rings, but will not keep them from sticking again if that is the issue.

Peter

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Hmmmm.... faulty injectors??? Glad I have a carbie!.

(Let's see if that gets good ol' Tom riled up enough to come back on to TMC!)

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  • 2 months later...

I noticed my sunsetter had fuel in crankcase this spring. I changed the oil last fall when winterizing so I know it was fresh. When I put the boat in this spring it started up fine but after I opened it up (w.o.t.) and then slowed to put it on the lift it started idling very rough. I was getting a "sucking" sound from throttle body and could see fuel in water behind the boat coming from exhaust. Changed oil, oil filter and mechanical fuel pump, took the boat out and seemed to be fixed until I slowed again after opening it up, same problem. Apparently it was a stuck needle valve in the fuel injection that was dumping way too much fuel into the engine. I pick the boat up tomorrow and will see if that fixes it this weekend.

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