making oil why?

[dan4fish]

whats the deal with 4 strokes making oil and why do they do it?
I have a suzuki 115 and I have not noticed it making oil. but what do I do if it starts.
and also what are the neg effects of making oil

[Glen E]

if you are "making oil" - (getting a rise in the dipstick):

making oil happens in 4 strokes that usually are not broken in correctly and the rings are not seated correctly or there is a stuck ring from too much carbon. here' s the way to treat this problem:
1. change your oil
2. take it out and run it hard (WOT) under load at least 5 min everytime you go out.
3. run quikleen or Ringfree for a few tanks...
4. Try not to troll too much and don't baby it - run it above 4000 as much as you can.

this usually happens when people "baby" the break in....

if it is coming up quick - like in one tank - it's a leak in the fuel delivery system or leaky injector..

[seahorse]

Due to the fuel dilution problem that can occur in 4-stroke outboards, newer Yamaha and Verado owners manuals state to change oil more often than the 100 hrs or annual interval when doing a lot of low speed running or trolling.

I'm sure Glen E can confirm the Merc info for me.

Oil dilution is one of the items addressed in the specifications for the new FC-W oil certification requirements due to it being a common problem.

Besides improper break-in, oil dilution can be caused by thermostats not allowing the motor to come up to optimum temperature at low speeds, and by over-propping the engine.

[Brad1]

I heard an alternate explanation. My Brother was experiencing the "making oil" problem with his Yamaha F115. He contacted Andy Jr. at SIM and according to Andy, my brother was using a prop that was not allowing the engine to reach high enough RPM at WOT. Since the throttle was in the WOT position, the engine was giving it the maximum amount of fuel. But since the motor was not turning at a high enough RPM, the fuel was not being consumed. Andy recommended a different prop which would allow my Brother's outboard to gain several hundred more RPM at WOT. I believe that corrected the problem.

[A1 Outboard]

Brad1 - 8/2/2007 8:06 AM
I heard an alternate explanation.
... my brother was using a prop that was not allowing the engine to reach high enough RPM at WOT. Since the throttle was in the WOT position, the engine was giving it the maximum amount of fuel. But since the motor was not turning at a high enough RPM, the fuel was not being consumed.

That is what is known as overpropping and was mentioned in the response just before yours.

It is a prevalent problem because many boat companies supply the wrong prop with a pre-rigged boat and do not take into account the load that a customer puts in the boat on a normal day on the water.