Oil pressure in a F90tlr problem... Over pressure!

[Strikefast]

I was running my skiff when it bogged down a bit. When lowered to under 1/2 throttle it was ok. Eventually the motor quit and it blew some white smoke out if the exhaust.

I let it sit for a bit and went to ck the oil with the dip stick. When pulled the dip stick, oil pushed out like a fountain! After a tow and the boat sitting overnight, the same thing happened when I pulled the dip stick today

Is there a PVC valve on these or some other pressure relief valve that may be blocked? The oil was clear and looked like it was new. No water or fuel intrusion that I could see.....

[boscoe99]

There is no PVC valve in an F90TLR.

If it were my motor I would drain the oil and then refill.

Tilt the motor all of the way up for five minutes prior to draining the oil. This will ensure that any oil that is trapped within the block can get back to the oil pan.

While the motor is tilted up, remove the drain plug. No oil should spill out. Hold a bucket under the drain port in one hand and with the other hand use the tilt button to lower the motor all of the way downward. If you are careful you won't spill a drop. When the oil has stopped draining carefully reinstall the drain plug being careful not to cross thread it or over tighten it.

Position the motor to the straight up and down position. Remove the old filter and install a new one. Add just enough oil to get the oil level to the middle of the markings on the dip stick. Start the motor and run it for about a minute to refill the oil filter. Stop the motor. Tilt the motor up about half way for about five minutes. Move it back down to the vertical position. Check the oil level. Add oil only if needed to get the level back to the mid-point between the min and max points. Be careful not to add to much. You don't want it going over the mid point on the dip stick.

Let us know how it runs after doing this.

[Strikefast]

Still curious

I would still like to know why the pressure built up... Do you think changing the oil and filter is the cure?

Guess you are looking at the filter being clogged? Is their somewhere that the lines could be clogged?

[boscoe99]

I am thinking too much oil. Which is why it gushed out when the dipstick was removed.

[Strikefast]

Hmmm, it ran fine last season with the same amount of oil. Had the water pump replaced but nothing done to the crankcase..... I'll try it and see. Thanks for the info.

[Strikefast]

Oil and gas

Well I just pulled the oil drain plug and got a gallon of water thin oil and gas mix out of the crankcase.

Might need surgery......lol oh well my luck....

[boscoe99]

The crank case breather tube runs from the top of the valve cover to the intake silencer. Remove the tube from the valve cover when the motor is running, hold your thumb over the end of the tube, and see if excess air flow is coming from the valve cover.

But I don't think the rings are bad resulting in excessive blow by. Now that you have found water in the oil I am more convinced than I was before.

But everything is a guess at this point.

[Strikefast]

Not water just gas

Sorry I just said "water thin" to describe the gas diluted the oil to the viscosity of water....

[99yam40]

yep the comment OP made in original post about oil not being contaminated with fuel made me wonder what was going on and how he knew that.

time to look at all the normal making oil causes

[Strikefast]

Thabjs

Thanks guys, I will ck for making oil problems as well as to see if the fuel pump diaphram is leaking g gas into the crankcase. Always something...

[CatCam]

Check your T-stat too!

[Strikefast]

Will do... Am going to replace oil, filter, thermostat, and fuel pump if necessary..

[TownsendsFJR1300]

Well I just pulled the oil drain plug and got a gallon of water thin oil and gas mix out of the crankcase.

He's got excess FUEL in the oil diluting it, overfilling the crankcase, not water..

Time to look at the fuel pump, or *** for a major leak of fuel into the crankcase.


.

[Strikefast]

Scott, I think you may be right. I have way too much gas in the oil for it to have been a build up or making oil I think.

I got over a gallon of gas oil mix that was as thin as water flowing. To dilute 4.5 quarts of oil to that thinness it would take a load of gas......

Raining here rt now so I will put the pump in the morning to see if any gaskets are cut or if the diaphram is leaking..

[99yam40]

4.5 quarts of oil is already over a gallon, so hard to tell how much gas you had in it.