UOA: 2019 Yamaha Waverunner FX Cruiser HO - Amsoil Marine 10W-40

[jtwrace]

Here is my oil change using Blackstone Labs for analysis with AMSOIL INC 10W-40 Marine in a Yamaha 1.8L

* My first oil change was at 5 hrs using Yamalube and then at 10 hrs which I then switched to Amsoil. All oil changes have used the OEM Oil Filter as shown.

** Just to note I have used Ethanol Free Gas exclusively and have used Sta-Bil Marine 360 in every top off.

As you can see from the photos of the filter, there are small ( > 20 micron) aluminum specs. Nothing to be concerned about as it's normal and the oil concludes that as well.

For those that are curious, it's $28 for the oil analysis. This is very common in Aerospace and many other industries so I'm not that far off...well, OK, maybe a little but it's my world.

Blackstone Laboratories | Oil Analysis - Learn What's Going On In Your Engine
https://www.amsoil.com/shop/by-produ...?code=WCFQT-EA

***After me studying the first report, I requested a retest of the fuel content which is the reason for the amended report. The Flashpoint temp as 380°F, just barely above the “should be “ value of >375°F. Amsoil begins with a Flashpoint temp of 464°F when new, fuel dilution is the only means that the Flashpoint temp could be reduced by 84°F. This would be more than enough fuel dilution to reduce the viscosity to the 30-weight range.

 

[jtwrace]

So, after thinking about this for a bit. I figured it was time to investigate the fuel injectors as that's typically the cause for such high fuel in oil. As you can see, the #4 injector passed QC and was defective. It was simply missed as I'm sure not every injector is tested when making many of them. They typically spot check an item like this so who knows how many are out there!


Look at the right (cyl 4) injector Feathering


Leak test


Static Volume Test


Static flow rate for 15 seconds @ 3 bar


New injector on right for cylinder 4 solved the issue of feathering shown above.

 

[3 green tornados]

Thank you for the information!