1.8 Fuel Dilution

[Cavitation]

2022 1.8 my oil samples have been coming back with high fuel dilution in both engines. It is affecting viscosity and flashpoint and it said nothing to be concerned about yet, but I still don't like it. Is this common for these engines or do I have a problem? Even last years samples at 50 hours showed fuel dilution.

 

[FSH 210 Sport]

2022 1.8 my oil samples have been coming back with high fuel dilution in both engines. It is affecting viscosity and flashpoint and it said nothing to be concerned about yet, but I still don't like it. Is this common for these engines or do I have a problem? Even last years samples at 50 hours showed fuel dilution.

What is the % of dilution?

 

[Cavitation]

What is the % of dilution?

3%. cSt down to 9.4 when it should be 11.6-14.8.

 

[biffdotorg]

I think the question was diluted with what? water? or Oil?

Are you experiencing engine problems, and if so what? What would cause you to look for a problem in the first place? or do you do these tests on all your engines?

 

[Neutron]

I think the question was diluted with what? water? or Oil?

Are you experiencing engine problems, and if so what? What would cause you to look for a problem in the first place? or do you do these tests on all your engines?

Fuel Dilution is they percentage of fuel in the oil sample. All engines get some percentage of fuel in the oil. You just dont want too much because it will lessen the wear protection on components

 

[Neutron]

2022 1.8 my oil samples have been coming back with high fuel dilution in both engines. It is affecting viscosity and flashpoint and it said nothing to be concerned about yet, but I still don't like it. Is this common for these engines or do I have a problem? Even last years samples at 50 hours showed fuel dilution.

Personally i wouldn't be too concerned, these engines still use 10w40 not 0w oil probably because they dont have real tight tolerances. Not many engine/bearing failures in these engines

 

[biffdotorg]

Fuel Dilution is they percentage of fuel in the oil sample. All engines get some percentage of fuel in the oil. You just dont want too much because it will lessen the wear protection on components

Blow by? I guess that’s the only way I could see it happening.

 

[Ed255fsh]

Not in a 1.8 , but had in car . bad rings or valves.

 

[biffdotorg]

Not in a 1.8 , but had in car . bad rings or valves.

Exactly. So unless rings are starting to wear or bad seat on the rings how else does fuel get into the oil? And why would anyone even test for this unless they show some sort of symptoms or the engine has tons of hours and it was a way to check blow by.

On a daily new 222, I would see no reason in the works to do this.

 

[Neutron]

Ring, valve guide/seals are the only way it mixes with oil. I can see that during break in the percentage could be higher till the rings seat in fully.
Out of all the Yamaha oil changes i have done, i have never seen one overfilled or a high smell of gas in the oil unless there was an issue i was repairing.

 

[Bottom Bracket]

Sniff your dipstick.