2004 Optimax 135 Oil Usage

I have loved the engine, but starting this year, it started using much more oil than normal. On a recent week long trip it became more obvious, I did not calculate exactly, but somewhere in the ratio of 25:1, which is way more than usual. I usually only go through about 1.5 -2 gallons of oil a year and almost used a whole gallon on a tank and a half of fuel (40 gallons). Also seeing black buildup on exhaust port and smelling exhaust at slow speeds which has never happened before. Any ideas? Dealer wants it dropped off for 1-2 weeks to look at it and do not want to be without boat for that long at this point if it is something I can fix myself. Thanks in advance for any help.

Being a direct injected motor the oil and gas do not mix until it gets in the cylinder. The oil is carried through the crankcase with the air (like a typical 2 stroke, with the conventional 2 stroke also carrying the gas (so gas/oil/air) through the crankcase.

If you are running "oil rich" it must be either the oil pump itself that is going, or the ECM (engine computer) which tells the pump "how much oil to pump".

Without getting the motor on a diagnostic computer it's tough to "guess" at what may be the problem. Even to check the "oil flow rate" from the pump requires the motor to be hooked up to a DDT (diagnostic computer). Don't you love "advanced technology".

What you can (maybe) check in the driveway is the oil lines - from your remote tank to the (on the motor) tank - make sure there is no leaks anywhere and then from the onboard tank to the oil pump.

There is seven different oil feed lines (tubes) going from the oil pump - six to the crankcase and one to the compressor but those are "after the fact" - if the pump is doing it's thing, sending between 400:1 and 60:1 (dependent on rpms) and it's leaking in any of those lines, it shouldn't effect the overall consumption (although it would be a separate issue).

Otherwise, you are going to have to get the motor in and "hooked up" to find out what is wrong.

Thanks for the help. That is what I was reading elsewhere as well. I have checked for leaks and other than some minor drips, nothing that would indicate any minor or major issue in that regard. Would the O-ring on the remote tank failing cause an issue with pressure and the system. I did notice that there was oil on the cap with the hoses attached, but not any amount worth noting. I have just never seen oil there before when filling.

Yes, new technology is always a joy to troubleshoot.

Yes, a bad o-ring (could) result in the remote tank not getting/retaining enough pressure to fill the tank on the motor (uses pressure from the crankcase to force oil from the remote tank to refill the tank on the motor).

So while that is/could be an "issue", it would not cause the over use of oil - unless the oil was being forced out of the cap into the bilge of your boat.

What is normal pressure in the remote tank?
On my 2004 200HP 2.5L carb engine I see 2.5b lbs crankcase pressure that drops to 2 lbs at higher rpm. Is that normal?

Do you have smartcraft guages ?
has the break in, not been reset 120 mins ? (double oil usage )?